diff --git a/core/alien/alien.factor b/core/alien/alien.factor
index d0adec1fcf..cfa9fb2e16 100755
--- a/core/alien/alien.factor
+++ b/core/alien/alien.factor
@@ -39,7 +39,7 @@ M: alien equal?
         2dup [ expired? ] either? [
             [ expired? ] both?
         ] [
-            [ alien-address ] 2apply =
+            [ alien-address ] bi@ =
         ] if
     ] [
         2drop f
diff --git a/core/assocs/assocs.factor b/core/assocs/assocs.factor
index 196ec614b7..b911faf672 100755
--- a/core/assocs/assocs.factor
+++ b/core/assocs/assocs.factor
@@ -115,7 +115,7 @@ M: assoc assoc-clone-like ( assoc exemplar -- newassoc )
     swap [ swapd set-at ] curry assoc-each ;
 
 : union ( assoc1 assoc2 -- union )
-    2dup [ assoc-size ] 2apply + pick new-assoc
+    2dup [ assoc-size ] bi@ + pick new-assoc
     [ rot update ] keep [ swap update ] keep ;
 
 : diff ( assoc1 assoc2 -- diff )
diff --git a/core/bit-arrays/bit-arrays-tests.factor b/core/bit-arrays/bit-arrays-tests.factor
index 5774b86e45..e28c16c3c2 100755
--- a/core/bit-arrays/bit-arrays-tests.factor
+++ b/core/bit-arrays/bit-arrays-tests.factor
@@ -21,7 +21,7 @@ IN: bit-arrays.tests
     { t f t } { f t f }
 ] [
     { t f t } >bit-array dup clone dup [ not ] change-each
-    [ >array ] 2apply
+    [ >array ] bi@
 ] unit-test
 
 [
diff --git a/core/bootstrap/stage2.factor b/core/bootstrap/stage2.factor
index f472e0158f..bbb2e44843 100755
--- a/core/bootstrap/stage2.factor
+++ b/core/bootstrap/stage2.factor
@@ -23,7 +23,7 @@ SYMBOL: bootstrap-time
 
 : load-components ( -- )
     "exclude" "include"
-    [ get-global " " split [ empty? not ] subset ] 2apply
+    [ get-global " " split [ empty? not ] subset ] bi@
     seq-diff
     [ "bootstrap." prepend require ] each ;
 
diff --git a/core/classes/algebra/algebra.factor b/core/classes/algebra/algebra.factor
index e2206213a6..2945bd2546 100755
--- a/core/classes/algebra/algebra.factor
+++ b/core/classes/algebra/algebra.factor
@@ -67,7 +67,7 @@ C: <anonymous-complement> anonymous-complement
     members>> [ class< ] with all? ;
 
 : anonymous-complement< ( first second -- ? )
-    [ class>> ] 2apply swap class< ;
+    [ class>> ] bi@ swap class< ;
 
 : (class<) ( first second -- -1/0/1 )  
     {
diff --git a/core/classes/mixin/mixin.factor b/core/classes/mixin/mixin.factor
index 85a6fb241d..eb6b3bd6e2 100755
--- a/core/classes/mixin/mixin.factor
+++ b/core/classes/mixin/mixin.factor
@@ -47,8 +47,8 @@ TUPLE: mixin-instance loc class mixin ;
 M: mixin-instance equal?
     {
         { [ over mixin-instance? not ] [ f ] }
-        { [ 2dup [ mixin-instance-class ] 2apply = not ] [ f ] }
-        { [ 2dup [ mixin-instance-mixin ] 2apply = not ] [ f ] }
+        { [ 2dup [ mixin-instance-class ] bi@ = not ] [ f ] }
+        { [ 2dup [ mixin-instance-mixin ] bi@ = not ] [ f ] }
         { [ t ] [ t ] }
     } cond 2nip ;
 
diff --git a/core/compiler/tests/curry.factor b/core/compiler/tests/curry.factor
index d2e7115f8f..61d20fd8ab 100755
--- a/core/compiler/tests/curry.factor
+++ b/core/compiler/tests/curry.factor
@@ -10,7 +10,7 @@ IN: compiler.tests
 [ 3 ] [ 5 2 [ [ - ] 2curry 9 swap call /i ] compile-call ] unit-test
 [ 3 ] [ 5 2 [ [ - ] 2curry >r 9 r> call /i ] compile-call ] unit-test
 
-[ -10 -20 ] [ 10 20 -1 [ [ * ] curry 2apply ] compile-call ] unit-test
+[ -10 -20 ] [ 10 20 -1 [ [ * ] curry bi@ ] compile-call ] unit-test
 
 [ [ 5 2 - ] ] [ 5 [ [ 2 - ] curry ] compile-call >quotation ] unit-test
 [ [ 5 2 - ] ] [ [ 5 [ 2 - ] curry ] compile-call >quotation ] unit-test
diff --git a/core/compiler/tests/templates.factor b/core/compiler/tests/templates.factor
index 8a33d57fe7..081a8fd47c 100755
--- a/core/compiler/tests/templates.factor
+++ b/core/compiler/tests/templates.factor
@@ -72,13 +72,13 @@ unit-test
 ] unit-test
 
 [ 12 13 ] [
-    -12 -13 [ [ 0 swap fixnum-fast ] 2apply ] compile-call
+    -12 -13 [ [ 0 swap fixnum-fast ] bi@ ] compile-call
 ] unit-test
 
 [ -1 2 ] [ 1 2 [ >r 0 swap fixnum- r> ] compile-call ] unit-test
 
 [ 12 13 ] [
-    -12 -13 [ [ 0 swap fixnum- ] 2apply ] compile-call
+    -12 -13 [ [ 0 swap fixnum- ] bi@ ] compile-call
 ] unit-test
 
 [ 1 ] [
diff --git a/core/cpu/arm/architecture/architecture.factor b/core/cpu/arm/architecture/architecture.factor
index 8742a693cb..563dd10bc4 100755
--- a/core/cpu/arm/architecture/architecture.factor
+++ b/core/cpu/arm/architecture/architecture.factor
@@ -63,7 +63,7 @@ M: arm-backend load-indirect ( obj reg -- )
 
 M: immediate load-literal
     over v>operand small-enough? [
-        [ v>operand ] 2apply swap MOV
+        [ v>operand ] bi@ swap MOV
     ] [
         v>operand load-indirect
     ] if ;
@@ -322,10 +322,10 @@ M: arm-backend fp-shadows-int? ( -- ? ) f ;
 
 ! Alien intrinsics
 M: arm-backend %unbox-byte-array ( dst src -- )
-    [ v>operand ] 2apply byte-array-offset ADD ;
+    [ v>operand ] bi@ byte-array-offset ADD ;
 
 M: arm-backend %unbox-alien ( dst src -- )
-    [ v>operand ] 2apply alien-offset <+> LDR ;
+    [ v>operand ] bi@ alien-offset <+> LDR ;
 
 M: arm-backend %unbox-f ( dst src -- )
     drop v>operand 0 MOV ;
diff --git a/core/cpu/ppc/allot/allot.factor b/core/cpu/ppc/allot/allot.factor
index df0a08a86d..6c37fce4f1 100755
--- a/core/cpu/ppc/allot/allot.factor
+++ b/core/cpu/ppc/allot/allot.factor
@@ -33,7 +33,7 @@ IN: cpu.ppc.allot
     f fresh-object ;
 
 M: ppc-backend %box-float ( dst src -- )
-    [ v>operand ] 2apply %allot-float 12 MR ;
+    [ v>operand ] bi@ %allot-float 12 MR ;
 
 : %allot-bignum ( #digits -- )
     #! 1 cell header, 1 cell length, 1 cell sign, + digits
diff --git a/core/cpu/ppc/architecture/architecture.factor b/core/cpu/ppc/architecture/architecture.factor
index 1daf3ac622..903ac32df9 100755
--- a/core/cpu/ppc/architecture/architecture.factor
+++ b/core/cpu/ppc/architecture/architecture.factor
@@ -71,7 +71,7 @@ M: ds-loc loc>operand ds-loc-n cells neg ds-reg swap ;
 M: rs-loc loc>operand rs-loc-n cells neg rs-reg swap ;
 
 M: immediate load-literal
-    [ v>operand ] 2apply LOAD ;
+    [ v>operand ] bi@ LOAD ;
 
 M: ppc-backend load-indirect ( obj reg -- )
     [ 0 swap LOAD32 rc-absolute-ppc-2/2 rel-literal ] keep
@@ -138,7 +138,7 @@ M: ppc-backend %replace
     >r v>operand r> loc>operand STW ;
 
 M: ppc-backend %unbox-float ( dst src -- )
-    [ v>operand ] 2apply float-offset LFD ;
+    [ v>operand ] bi@ float-offset LFD ;
 
 M: ppc-backend %inc-d ( n -- ) ds-reg dup rot cells ADDI ;
 
@@ -291,10 +291,10 @@ M: ppc-backend %unbox-small-struct
 
 ! Alien intrinsics
 M: ppc-backend %unbox-byte-array ( dst src -- )
-    [ v>operand ] 2apply byte-array-offset ADDI ;
+    [ v>operand ] bi@ byte-array-offset ADDI ;
 
 M: ppc-backend %unbox-alien ( dst src -- )
-    [ v>operand ] 2apply alien-offset LWZ ;
+    [ v>operand ] bi@ alien-offset LWZ ;
 
 M: ppc-backend %unbox-f ( dst src -- )
     drop 0 swap v>operand LI ;
diff --git a/core/cpu/x86/allot/allot.factor b/core/cpu/x86/allot/allot.factor
index f837a92504..5519a9a8d5 100755
--- a/core/cpu/x86/allot/allot.factor
+++ b/core/cpu/x86/allot/allot.factor
@@ -101,6 +101,6 @@ M: x86-backend %box-alien ( dst src -- )
         ] %allot
         "end" get JMP
         "f" resolve-label
-        f [ v>operand ] 2apply MOV
+        f [ v>operand ] bi@ MOV
         "end" resolve-label
     ] with-scope ;
diff --git a/core/cpu/x86/architecture/architecture.factor b/core/cpu/x86/architecture/architecture.factor
index f993639c05..31fa4c8e4b 100755
--- a/core/cpu/x86/architecture/architecture.factor
+++ b/core/cpu/x86/architecture/architecture.factor
@@ -109,9 +109,9 @@ M: x86-backend %dispatch-label ( word -- )
     0 cell, rc-absolute-cell rel-word ;
 
 M: x86-backend %unbox-float ( dst src -- )
-    [ v>operand ] 2apply float-offset [+] MOVSD ;
+    [ v>operand ] bi@ float-offset [+] MOVSD ;
 
-M: x86-backend %peek [ v>operand ] 2apply MOV ;
+M: x86-backend %peek [ v>operand ] bi@ MOV ;
 
 M: x86-backend %replace swap %peek ;
 
@@ -162,10 +162,10 @@ M: x86-backend %return ( -- ) 0 %unwind ;
 
 ! Alien intrinsics
 M: x86-backend %unbox-byte-array ( dst src -- )
-    [ v>operand ] 2apply byte-array-offset [+] LEA ;
+    [ v>operand ] bi@ byte-array-offset [+] LEA ;
 
 M: x86-backend %unbox-alien ( dst src -- )
-    [ v>operand ] 2apply alien-offset [+] MOV ;
+    [ v>operand ] bi@ alien-offset [+] MOV ;
 
 M: x86-backend %unbox-f ( dst src -- )
     drop v>operand 0 MOV ;
diff --git a/core/debugger/debugger.factor b/core/debugger/debugger.factor
index a7937cdb9d..033ae0680c 100755
--- a/core/debugger/debugger.factor
+++ b/core/debugger/debugger.factor
@@ -82,7 +82,7 @@ ERROR: assert got expect ;
 : depth ( -- n ) datastack length ;
 
 : trim-datastacks ( seq1 seq2 -- seq1' seq2' )
-    2dup [ length ] 2apply min tuck tail >r tail r> ;
+    2dup [ length ] bi@ min tuck tail >r tail r> ;
 
 ERROR: relative-underflow stack ;
 
diff --git a/core/dlists/dlists-tests.factor b/core/dlists/dlists-tests.factor
index 2bc0e6a3fb..28db6e1cbd 100755
--- a/core/dlists/dlists-tests.factor
+++ b/core/dlists/dlists-tests.factor
@@ -63,7 +63,7 @@ IN: dlists.tests
 [ 0 ] [ <dlist> 1 over push-front dup pop-front* dlist-length ] unit-test
 
 : assert-same-elements
-    [ prune natural-sort ] 2apply assert= ;
+    [ prune natural-sort ] bi@ assert= ;
 
 : dlist-push-all [ push-front ] curry each ;
 
diff --git a/core/effects/effects.factor b/core/effects/effects.factor
index 23e8daf122..aed4a64c6c 100755
--- a/core/effects/effects.factor
+++ b/core/effects/effects.factor
@@ -18,8 +18,8 @@ TUPLE: effect in out terminated? ;
         { [ dup not ] [ t ] }
         { [ over effect-terminated? ] [ t ] }
         { [ dup effect-terminated? ] [ f ] }
-        { [ 2dup [ effect-in length ] 2apply > ] [ f ] }
-        { [ 2dup [ effect-height ] 2apply = not ] [ f ] }
+        { [ 2dup [ effect-in length ] bi@ > ] [ f ] }
+        { [ 2dup [ effect-height ] bi@ = not ] [ f ] }
         { [ t ] [ t ] }
     } cond 2nip ;
 
diff --git a/core/generator/registers/registers.factor b/core/generator/registers/registers.factor
index e03923e860..aac1b2cdc6 100755
--- a/core/generator/registers/registers.factor
+++ b/core/generator/registers/registers.factor
@@ -79,7 +79,7 @@ M: ds-loc minimal-ds-loc* ds-loc-n min ;
 M: ds-loc operand-class* ds-loc-class ;
 M: ds-loc set-operand-class set-ds-loc-class ;
 M: ds-loc live-loc?
-    over ds-loc? [ [ ds-loc-n ] 2apply = not ] [ 2drop t ] if ;
+    over ds-loc? [ [ ds-loc-n ] bi@ = not ] [ 2drop t ] if ;
 
 ! A retain stack location.
 TUPLE: rs-loc n class ;
@@ -89,7 +89,7 @@ TUPLE: rs-loc n class ;
 M: rs-loc operand-class* rs-loc-class ;
 M: rs-loc set-operand-class set-rs-loc-class ;
 M: rs-loc live-loc?
-    over rs-loc? [ [ rs-loc-n ] 2apply = not ] [ 2drop t ] if ;
+    over rs-loc? [ [ rs-loc-n ] bi@ = not ] [ 2drop t ] if ;
 
 UNION: loc ds-loc rs-loc ;
 
@@ -206,7 +206,7 @@ INSTANCE: constant value
     %move ;
 
 : %move ( dst src -- )
-    2dup [ move-spec ] 2apply 2array {
+    2dup [ move-spec ] bi@ 2array {
         { { f f } [ %move-bug ] }
         { { f unboxed-c-ptr } [ %move-bug ] }
         { { f unboxed-byte-array } [ %move-bug ] }
@@ -318,7 +318,7 @@ M: phantom-stack cut-phantom
 
 : phantoms ( -- phantom phantom ) phantom-d get phantom-r get ;
 
-: each-phantom ( quot -- ) phantoms rot 2apply ; inline
+: each-phantom ( quot -- ) phantoms rot bi@ ; inline
 
 : finalize-heights ( -- ) [ finalize-height ] each-phantom ;
 
@@ -442,7 +442,7 @@ M: loc lazy-store
 : fast-shuffle? ( live-locs -- ? )
     #! Test if we have enough free registers to load all
     #! shuffle inputs at once.
-    T{ int-regs } free-vregs [ length ] 2apply <= ;
+    T{ int-regs } free-vregs [ length ] bi@ <= ;
 
 : finalize-locs ( -- )
     #! Perform any deferred stack shuffling.
@@ -488,7 +488,7 @@ M: loc lazy-store
 
 : phantom&spec ( phantom spec -- phantom' spec' )
     [ length f pad-left ] keep
-    [ <reversed> ] 2apply ; inline
+    [ <reversed> ] bi@ ; inline
 
 : phantom&spec-agree? ( phantom spec quot -- ? )
     >r phantom&spec r> 2all? ; inline
@@ -520,7 +520,7 @@ M: loc lazy-store
     swap lazy-load ;
 
 : output-vregs ( -- seq seq )
-    +output+ +clobber+ [ get [ get ] map ] 2apply ;
+    +output+ +clobber+ [ get [ get ] map ] bi@ ;
 
 : clash? ( seq -- ? )
     phantoms append [
diff --git a/core/hashtables/hashtables.factor b/core/hashtables/hashtables.factor
index 4527d2044d..5ac49ffa2f 100755
--- a/core/hashtables/hashtables.factor
+++ b/core/hashtables/hashtables.factor
@@ -156,7 +156,7 @@ M: hashtable clone
 
 M: hashtable equal?
     over hashtable? [
-        2dup [ assoc-size ] 2apply number=
+        2dup [ assoc-size ] bi@ number=
         [ assoc= ] [ 2drop f ] if
     ] [ 2drop f ] if ;
 
diff --git a/core/heaps/heaps-tests.factor b/core/heaps/heaps-tests.factor
index 0b3123c87b..77560c7444 100755
--- a/core/heaps/heaps-tests.factor
+++ b/core/heaps/heaps-tests.factor
@@ -66,8 +66,8 @@ IN: heaps.tests
         dup heap-data clone swap
     ] keep 3 /i [ 2dup >r delete-random r> heap-delete ] times
     heap-data
-    [ [ entry-key ] map ] 2apply
-    [ natural-sort ] 2apply ;
+    [ [ entry-key ] map ] bi@
+    [ natural-sort ] bi@ ;
 
 11 [
     [ t ] swap [ 2^ delete-test sequence= ] curry unit-test
diff --git a/core/inference/class/class.factor b/core/inference/class/class.factor
index 7764fd4fd1..ed36ca4890 100755
--- a/core/inference/class/class.factor
+++ b/core/inference/class/class.factor
@@ -26,8 +26,8 @@ C: <literal-constraint> literal-constraint
 M: literal-constraint equal?
     over literal-constraint? [
         2dup
-        [ literal-constraint-literal ] 2apply eql? >r
-        [ literal-constraint-value ] 2apply = r> and
+        [ literal-constraint-literal ] bi@ eql? >r
+        [ literal-constraint-value ] bi@ = r> and
     ] [
         2drop f
     ] if ;
diff --git a/core/inference/inference-tests.factor b/core/inference/inference-tests.factor
index 1cc1548a3d..84014512aa 100755
--- a/core/inference/inference-tests.factor
+++ b/core/inference/inference-tests.factor
@@ -224,7 +224,7 @@ DEFER: do-crap*
 MATH: xyz
 M: fixnum xyz 2array ;
 M: float xyz
-    [ 3 ] 2apply swapd >r 2array swap r> 2array swap ;
+    [ 3 ] bi@ swapd >r 2array swap r> 2array swap ;
 
 [ [ xyz ] infer ] [ inference-error? ] must-fail-with
 
diff --git a/core/io/files/files-tests.factor b/core/io/files/files-tests.factor
index b78f7667a6..9920d8d25c 100755
--- a/core/io/files/files-tests.factor
+++ b/core/io/files/files-tests.factor
@@ -117,7 +117,7 @@ io.encodings.utf8 ;
 
 [ ] [ "test-quux.txt" temp-file ascii [ [ yield "Hi" write ] "Test" spawn drop ] with-file-writer ] unit-test
 
-[ ] [ "test-quux.txt" "quux-test.txt" [ temp-file ] 2apply move-file ] unit-test
+[ ] [ "test-quux.txt" "quux-test.txt" [ temp-file ] bi@ move-file ] unit-test
 [ t ] [ "quux-test.txt" temp-file exists? ] unit-test
 
 [ ] [ "quux-test.txt" temp-file delete-file ] unit-test
diff --git a/core/kernel/kernel-docs.factor b/core/kernel/kernel-docs.factor
index 0babb14fa7..457313724c 100755
--- a/core/kernel/kernel-docs.factor
+++ b/core/kernel/kernel-docs.factor
@@ -60,8 +60,8 @@ $nl
 { $subsection keep }
 { $subsection 2keep }
 { $subsection 3keep }
-{ $subsection 2apply }
-"A pair of utility words built from " { $link 2apply } ":"
+{ $subsection bi@ }
+"A pair of utility words built from " { $link bi@ } ":"
 { $subsection both? }
 { $subsection either? }
 "A looping combinator:"
@@ -376,7 +376,7 @@ HELP: 3keep
 { $values { "quot" "a quotation with stack effect " { $snippet "( x y z -- )" } } { "x" object } { "y" object } { "z" object } }
 { $description "Call a quotation with three values on the stack, restoring the values when the quotation returns." } ;
 
-HELP: 2apply
+HELP: bi@
 { $values { "quot" "a quotation with stack effect " { $snippet "( obj -- )" } } { "x" object } { "y" object } }
 { $description "Applies the quotation to " { $snippet "x" } ", then to " { $snippet "y" } "." } ;
 
diff --git a/core/kernel/kernel.factor b/core/kernel/kernel.factor
index cbabeb6bfa..e2e0c0171a 100755
--- a/core/kernel/kernel.factor
+++ b/core/kernel/kernel.factor
@@ -199,6 +199,3 @@ GENERIC: construct-boa ( ... class -- tuple )
 : do-primitive ( number -- ) "Improper primitive call" throw ;
 
 PRIVATE>
-
-! Deprecated
-: 2apply bi@ ; inline
diff --git a/core/math/intervals/intervals-tests.factor b/core/math/intervals/intervals-tests.factor
index 5a3fe777b6..f6317e7475 100755
--- a/core/math/intervals/intervals-tests.factor
+++ b/core/math/intervals/intervals-tests.factor
@@ -169,7 +169,7 @@ IN: math.intervals.tests
 
 : random-interval ( -- interval )
     1000 random dup 2 1000 random + +
-    1 random zero? [ [ neg ] 2apply swap ] when
+    1 random zero? [ [ neg ] bi@ swap ] when
     4 random {
         { 0 [ [a,b] ] }
         { 1 [ [a,b) ] }
@@ -197,7 +197,7 @@ IN: math.intervals.tests
     0 pick interval-contains? over first { / /i } member? and [
         3drop t
     ] [
-        [ >r [ random-element ] 2apply ! 2dup . .
+        [ >r [ random-element ] bi@ ! 2dup . .
         r> first execute ] 3keep
         second execute interval-contains?
     ] if ;
@@ -214,7 +214,7 @@ IN: math.intervals.tests
 
 : comparison-test
     random-interval random-interval random-comparison
-    [ >r [ random-element ] 2apply r> first execute ] 3keep
+    [ >r [ random-element ] bi@ r> first execute ] 3keep
     second execute dup incomparable eq? [
         2drop t
     ] [
diff --git a/core/math/intervals/intervals.factor b/core/math/intervals/intervals.factor
index d1c458065f..cc51060f63 100755
--- a/core/math/intervals/intervals.factor
+++ b/core/math/intervals/intervals.factor
@@ -67,7 +67,7 @@ C: <interval> interval
 
 : (interval-op) ( p1 p2 quot -- p3 )
     2over >r >r
-    >r [ first ] 2apply r> call
+    >r [ first ] bi@ r> call
     r> r> [ second ] both? 2array ; inline
 
 : interval-op ( i1 i2 quot -- i3 )
@@ -108,7 +108,7 @@ C: <interval> interval
 
 : interval-intersect ( i1 i2 -- i3 )
     2dup and [
-        [ interval>points ] 2apply swapd
+        [ interval>points ] bi@ swapd
         [ swap endpoint> ] most
         >r [ swap endpoint< ] most r>
         make-interval
@@ -118,7 +118,7 @@ C: <interval> interval
 
 : interval-union ( i1 i2 -- i3 )
     2dup and [
-        [ interval>points 2array ] 2apply append points>interval
+        [ interval>points 2array ] bi@ append points>interval
     ] [
         2drop f
     ] if ;
@@ -131,17 +131,17 @@ C: <interval> interval
 
 : interval-singleton? ( int -- ? )
     interval>points
-    2dup [ second ] 2apply and
-    [ [ first ] 2apply = ]
+    2dup [ second ] bi@ and
+    [ [ first ] bi@ = ]
     [ 2drop f ] if ;
 
 : interval-length ( int -- n )
     dup
-    [ interval>points [ first ] 2apply swap - ]
+    [ interval>points [ first ] bi@ swap - ]
     [ drop 0 ] if ;
 
 : interval-closure ( i1 -- i2 )
-    dup [ interval>points [ first ] 2apply [a,b] ] when ;
+    dup [ interval>points [ first ] bi@ [a,b] ] when ;
 
 : interval-shift ( i1 i2 -- i3 )
     #! Inaccurate; could be tighter
@@ -163,7 +163,7 @@ C: <interval> interval
     [ min ] interval-op interval-closure ;
 
 : interval-interior ( i1 -- i2 )
-    interval>points [ first ] 2apply (a,b) ;
+    interval>points [ first ] bi@ (a,b) ;
 
 : interval-division-op ( i1 i2 quot -- i3 )
     >r 0 over interval-closure interval-contains?
@@ -186,13 +186,13 @@ SYMBOL: incomparable
 : left-endpoint-< ( i1 i2 -- ? )
     [ swap interval-subset? ] 2keep
     [ nip interval-singleton? ] 2keep
-    [ interval-from ] 2apply =
+    [ interval-from ] bi@ =
     and and ;
 
 : right-endpoint-< ( i1 i2 -- ? )
     [ interval-subset? ] 2keep
     [ drop interval-singleton? ] 2keep
-    [ interval-to ] 2apply =
+    [ interval-to ] bi@ =
     and and ;
 
 : (interval<) over interval-from over interval-from endpoint< ;
diff --git a/core/optimizer/def-use/def-use-tests.factor b/core/optimizer/def-use/def-use-tests.factor
index d5e8e2d75d..f22cce9fa8 100755
--- a/core/optimizer/def-use/def-use-tests.factor
+++ b/core/optimizer/def-use/def-use-tests.factor
@@ -99,7 +99,7 @@ namespaces assocs kernel sequences math tools.test words ;
 ] unit-test
 
 : regression-2 ( x y -- x.y )
-    [ p1 ] 2apply [
+    [ p1 ] bi@ [
         [
             rot
             [ 2swap [ swapd * -rot p2 +@ ] 2keep ]
diff --git a/core/optimizer/math/math.factor b/core/optimizer/math/math.factor
index 349cf88f17..abe48ec272 100755
--- a/core/optimizer/math/math.factor
+++ b/core/optimizer/math/math.factor
@@ -113,7 +113,7 @@ generic.standard system ;
 : post-process ( class interval node -- classes intervals )
     dupd won't-overflow?
     [ >r dup { f integer } member? [ drop fixnum ] when r> ] when
-    [ dup [ 1array ] when ] 2apply ;
+    [ dup [ 1array ] when ] bi@ ;
 
 : math-output-interval-1 ( node word -- interval )
     dup [
@@ -147,7 +147,7 @@ generic.standard system ;
 ] each
 
 : intervals ( node -- i1 i2 )
-    node-in-d first2 [ value-interval* ] 2apply ;
+    node-in-d first2 [ value-interval* ] bi@ ;
 
 : math-output-interval-2 ( node word -- interval )
     dup [
diff --git a/core/parser/parser.factor b/core/parser/parser.factor
index f8836217b5..36e5decd05 100755
--- a/core/parser/parser.factor
+++ b/core/parser/parser.factor
@@ -475,7 +475,7 @@ SYMBOL: interactive-vocabs
 
 : removed-definitions ( -- definitions )
     new-definitions old-definitions
-    [ get first2 union ] 2apply diff ;
+    [ get first2 union ] bi@ diff ;
 
 : smudged-usage ( -- usages referenced removed )
     removed-definitions filter-moved keys [
diff --git a/core/prettyprint/prettyprint.factor b/core/prettyprint/prettyprint.factor
index 6c557d873d..d294f95be6 100755
--- a/core/prettyprint/prettyprint.factor
+++ b/core/prettyprint/prettyprint.factor
@@ -114,7 +114,7 @@ SYMBOL: ->
 
 : remove-breakpoints ( quot pos -- quot' )
     over quotation? [
-        1+ cut [ (remove-breakpoints) ] 2apply
+        1+ cut [ (remove-breakpoints) ] bi@
         [ -> ] swap 3append
     ] [
         drop
diff --git a/core/quotations/quotations.factor b/core/quotations/quotations.factor
index 693e337959..c0f15a9388 100755
--- a/core/quotations/quotations.factor
+++ b/core/quotations/quotations.factor
@@ -12,7 +12,7 @@ M: curry call dup 3 slot swap 4 slot call ;
 M: compose call dup 3 slot swap 4 slot slip call ;
 
 M: wrapper equal?
-    over wrapper? [ [ wrapped ] 2apply = ] [ 2drop f ] if ;
+    over wrapper? [ [ wrapped ] bi@ = ] [ 2drop f ] if ;
 
 UNION: callable quotation curry compose ;
 
diff --git a/core/sequences/sequences-tests.factor b/core/sequences/sequences-tests.factor
index c545a9baee..3a30824084 100755
--- a/core/sequences/sequences-tests.factor
+++ b/core/sequences/sequences-tests.factor
@@ -169,13 +169,13 @@ unit-test
 
 [ f ] [ { "a" "b" "c" } { "a" "b" "c" } mismatch ] unit-test
 
-[ V{ } V{ } ] [ { "a" "b" } { "a" "b" } drop-prefix [ >vector ] 2apply ] unit-test
+[ V{ } V{ } ] [ { "a" "b" } { "a" "b" } drop-prefix [ >vector ] bi@ ] unit-test
 
-[ V{ "C" } V{ "c" } ] [ { "a" "b" "C" } { "a" "b" "c" } drop-prefix [ >vector ] 2apply ] unit-test
+[ V{ "C" } V{ "c" } ] [ { "a" "b" "C" } { "a" "b" "c" } drop-prefix [ >vector ] bi@ ] unit-test
 
 [ -1 1 "abc" <slice> ] must-fail
 
-[ V{ "a" "b" } V{ } ] [ { "X" "a" "b" } { "X" } drop-prefix [ >vector ] 2apply ] unit-test
+[ V{ "a" "b" } V{ } ] [ { "X" "a" "b" } { "X" } drop-prefix [ >vector ] bi@ ] unit-test
 
 [ -1 ] [ "ab" "abc" <=> ] unit-test
 [ 1 ] [ "abc" "ab" <=> ] unit-test
diff --git a/core/sequences/sequences.factor b/core/sequences/sequences.factor
index 111cf74ea2..1f2a6c5501 100755
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@@ -300,9 +300,9 @@ M: immutable-sequence clone-like like ;
 : change-nth ( i seq quot -- )
     [ >r nth r> call ] 3keep drop set-nth ; inline
 
-: min-length ( seq1 seq2 -- n ) [ length ] 2apply min ; inline
+: min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
 
-: max-length ( seq1 seq2 -- n ) [ length ] 2apply max ; inline
+: max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
 
 <PRIVATE
 
@@ -369,7 +369,7 @@ PRIVATE>
     (2each) each-integer ; inline
 
 : 2reverse-each ( seq1 seq2 quot -- )
-    >r [ <reversed> ] 2apply r> 2each ; inline
+    >r [ <reversed> ] bi@ r> 2each ; inline
 
 : 2reduce ( seq1 seq2 identity quot -- result )
     >r -rot r> 2each ; inline
@@ -460,7 +460,7 @@ M: sequence <=>
     [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
 
 : sequence= ( seq1 seq2 -- ? )
-    2dup [ length ] 2apply number=
+    2dup [ length ] bi@ number=
     [ mismatch not ] [ 2drop f ] if ; inline
 
 : move ( to from seq -- )
@@ -620,12 +620,12 @@ M: sequence <=>
             [ drop nip ]
             [ 2drop first ]
             [ >r drop first2 r> call ]
-            [ >r drop first3 r> 2apply ]
+            [ >r drop first3 r> bi@ ]
         } dispatch
     ] [
         drop
         >r >r halves r> r>
-        [ [ binary-reduce ] 2curry 2apply ] keep
+        [ [ binary-reduce ] 2curry bi@ ] keep
         call
     ] if ; inline
 
diff --git a/core/sorting/sorting.factor b/core/sorting/sorting.factor
index ab2ce21010..5f81b17187 100755
--- a/core/sorting/sorting.factor
+++ b/core/sorting/sorting.factor
@@ -32,7 +32,7 @@ DEFER: sort
     ] if ; inline
 
 : merge ( sorted1 sorted2 quot -- result )
-    >r [ [ <iterator> ] 2apply ] 2keep r>
+    >r [ [ <iterator> ] bi@ ] 2keep r>
     rot length rot length + <vector>
     [ (merge) ] keep underlying ; inline
 
diff --git a/core/splitting/splitting.factor b/core/splitting/splitting.factor
index 419a30dda4..9be1d5fc64 100755
--- a/core/splitting/splitting.factor
+++ b/core/splitting/splitting.factor
@@ -56,7 +56,7 @@ INSTANCE: groups sequence
     ] if ;
 
 : last-split1 ( seq subseq -- before after )
-    [ <reversed> ] 2apply split1 [ reverse ] 2apply
+    [ <reversed> ] bi@ split1 [ reverse ] bi@
     dup [ swap ] when ;
 
 : (split) ( separators n seq -- )
diff --git a/core/vectors/vectors-tests.factor b/core/vectors/vectors-tests.factor
index d990f5f31c..18aa0f3fa7 100755
--- a/core/vectors/vectors-tests.factor
+++ b/core/vectors/vectors-tests.factor
@@ -77,7 +77,7 @@ IN: vectors.tests
 
 [ f ] [
     V{ 1 2 3 4 } dup clone
-    [ underlying ] 2apply eq?
+    [ underlying ] bi@ eq?
 ] unit-test
 
 [ 0 ] [
diff --git a/core/vocabs/vocabs.factor b/core/vocabs/vocabs.factor
index f111b5bc74..886417b715 100755
--- a/core/vocabs/vocabs.factor
+++ b/core/vocabs/vocabs.factor
@@ -94,7 +94,7 @@ TUPLE: vocab-link name ;
 
 M: vocab-link equal?
     over vocab-link?
-    [ [ vocab-link-name ] 2apply = ] [ 2drop f ] if ;
+    [ [ vocab-link-name ] bi@ = ] [ 2drop f ] if ;
 
 M: vocab-link hashcode*
     vocab-link-name hashcode* ;
diff --git a/extra/benchmark/raytracer/raytracer.factor b/extra/benchmark/raytracer/raytracer.factor
index dbd1f5131b..3ec8cb4245 100755
--- a/extra/benchmark/raytracer/raytracer.factor
+++ b/extra/benchmark/raytracer/raytracer.factor
@@ -133,7 +133,7 @@ DEFER: create ( level c r -- scene )
     pick 1 = [ <sphere> nip ] [ create-group ] if ;
 
 : ss-point ( dx dy -- point )
-    [ oversampling /f ] 2apply 0.0 3float-array ;
+    [ oversampling /f ] bi@ 0.0 3float-array ;
 
 : ss-grid ( -- ss-grid )
     oversampling [ oversampling [ ss-point ] with map ] map ;
@@ -150,7 +150,7 @@ DEFER: create ( level c r -- scene )
 : pixel-grid ( -- grid )
     size reverse [
         size [
-            [ size 0.5 * - ] 2apply swap size
+            [ size 0.5 * - ] bi@ swap size
             3float-array
         ] with map
     ] map ;
diff --git a/extra/benchmark/reverse-complement/reverse-complement-tests.factor b/extra/benchmark/reverse-complement/reverse-complement-tests.factor
index c8d4714802..c66de87cb5 100755
--- a/extra/benchmark/reverse-complement/reverse-complement-tests.factor
+++ b/extra/benchmark/reverse-complement/reverse-complement-tests.factor
@@ -5,7 +5,7 @@ io.files kernel ;
 [ "c071aa7e007a9770b2fb4304f55a17e5" ] [
     "extra/benchmark/reverse-complement/reverse-complement-test-in.txt"
     "extra/benchmark/reverse-complement/reverse-complement-test-out.txt"
-    [ resource-path ] 2apply
+    [ resource-path ] bi@
     reverse-complement
 
     "extra/benchmark/reverse-complement/reverse-complement-test-out.txt"
diff --git a/extra/benchmark/spectral-norm/spectral-norm.factor b/extra/benchmark/spectral-norm/spectral-norm.factor
index 42bae7d0d1..7eddeefc1b 100644
--- a/extra/benchmark/spectral-norm/spectral-norm.factor
+++ b/extra/benchmark/spectral-norm/spectral-norm.factor
@@ -7,7 +7,7 @@ IN: benchmark.spectral-norm
 : fast-truncate >fixnum >float ; inline
 
 : eval-A ( i j -- n )
-    [ >float ] 2apply
+    [ >float ] bi@
     dupd + dup 1+ * 2 /f fast-truncate + 1+
     recip ; inline
 
diff --git a/extra/bitfields/bitfields.factor b/extra/bitfields/bitfields.factor
index 175f66f4a6..114809377b 100644
--- a/extra/bitfields/bitfields.factor
+++ b/extra/bitfields/bitfields.factor
@@ -63,7 +63,7 @@ M: check< summary drop "Number exceeds upper bound" ;
     [ range>accessor ] map ;
 
 : clear-range ( range -- num )
-    first2 dupd + [ 2^ 1- ] 2apply bitnot bitor ;
+    first2 dupd + [ 2^ 1- ] bi@ bitnot bitor ;
 
 : range>setter ( range -- quot )
     [
diff --git a/extra/boids/boids.factor b/extra/boids/boids.factor
index efa7216699..4ea20629c1 100644
--- a/extra/boids/boids.factor
+++ b/extra/boids/boids.factor
@@ -80,7 +80,7 @@ VAR: separation-radius
 
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-: relative-position ( self other -- v ) swap [ boid-pos ] 2apply v- ;
+: relative-position ( self other -- v ) swap [ boid-pos ] bi@ v- ;
 
 : relative-angle ( self other -- angle )
 over boid-vel -rot relative-position angle-between ;
diff --git a/extra/builder/benchmark/benchmark.factor b/extra/builder/benchmark/benchmark.factor
index 2f38462976..9e5e932831 100644
--- a/extra/builder/benchmark/benchmark.factor
+++ b/extra/builder/benchmark/benchmark.factor
@@ -19,11 +19,11 @@ IN: builder.benchmark
   2array ;
 
 : compare-tables ( old new -- table )
-  [ passing-benchmarks ] 2apply
+  [ passing-benchmarks ] bi@
   [ benchmark-difference ] with map ;
 
 : benchmark-deltas ( -- table )
-  "../benchmarks" "benchmarks" [ eval-file ] 2apply
+  "../benchmarks" "benchmarks" [ eval-file ] bi@
   compare-tables
   sort-values ;
 
diff --git a/extra/builder/util/util.factor b/extra/builder/util/util.factor
index 55ff38d408..92b9af41ef 100644
--- a/extra/builder/util/util.factor
+++ b/extra/builder/util/util.factor
@@ -88,7 +88,7 @@ USING: bootstrap.image bootstrap.image.download io.streams.null ;
 
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-: longer? ( seq seq -- ? ) [ length ] 2apply > ; 
+: longer? ( seq seq -- ? ) [ length ] bi@ > ; 
 
 : maybe-tail* ( seq n -- seq )
   2dup longer?
diff --git a/extra/calendar/calendar.factor b/extra/calendar/calendar.factor
index 0a808f53bd..6c29c0d1ac 100755
--- a/extra/calendar/calendar.factor
+++ b/extra/calendar/calendar.factor
@@ -185,7 +185,7 @@ M: number +second ( timestamp n -- timestamp )
     [ month>>  +month  ] keep
     [ year>>   +year   ] keep ; inline
 
-: +slots [ 2apply + ] curry 2keep ; inline
+: +slots [ bi@ + ] curry 2keep ; inline
 
 PRIVATE>
 
@@ -244,9 +244,9 @@ M: timestamp <=> ( ts1 ts2 -- n )
     [ >gmt tuple-slots ] compare ;
 
 : (time-) ( timestamp timestamp -- n )
-    [ >gmt ] 2apply
-    [ [ >date< julian-day-number ] 2apply - 86400 * ] 2keep
-    [ >time< >r >r 3600 * r> 60 * r> + + ] 2apply - + ;
+    [ >gmt ] bi@
+    [ [ >date< julian-day-number ] bi@ - 86400 * ] 2keep
+    [ >time< >r >r 3600 * r> 60 * r> + + ] bi@ - + ;
 
 M: timestamp time-
     #! Exact calendar-time difference
diff --git a/extra/calendar/format/format.factor b/extra/calendar/format/format.factor
index b0bd7c464f..26ed873fd3 100755
--- a/extra/calendar/format/format.factor
+++ b/extra/calendar/format/format.factor
@@ -182,7 +182,7 @@ M: timestamp year. ( timestamp -- )
     [
         [ month>> month-abbreviations nth write ] keep bl
         [ day>> number>string 2 32 pad-left write ] keep bl
-        dup now [ year>> ] 2apply = [
+        dup now [ year>> ] bi@ = [
             [ hour>> write-00 ] keep ":" write
             minute>> write-00
         ] [
diff --git a/extra/cocoa/dialogs/dialogs.factor b/extra/cocoa/dialogs/dialogs.factor
index ea77c496a2..606526a240 100644
--- a/extra/cocoa/dialogs/dialogs.factor
+++ b/extra/cocoa/dialogs/dialogs.factor
@@ -26,7 +26,7 @@ IN: cocoa.dialogs
     [ -> filenames CF>string-array ] [ drop f ] if ;
 
 : split-path ( path -- dir file )
-    "/" last-split1 [ <NSString> ] 2apply ;
+    "/" last-split1 [ <NSString> ] bi@ ;
 
 : save-panel ( path -- paths )
     <NSSavePanel> dup
diff --git a/extra/crypto/rsa/rsa.factor b/extra/crypto/rsa/rsa.factor
index ffb2a64b76..ccf17da4e8 100644
--- a/extra/crypto/rsa/rsa.factor
+++ b/extra/crypto/rsa/rsa.factor
@@ -24,7 +24,7 @@ C: <rsa> rsa
 : modulus-phi ( numbits -- n phi ) 
     #! Loop until phi is not divisible by the public key.
     dup rsa-primes [ * ] 2keep
-    [ 1- ] 2apply *
+    [ 1- ] bi@ *
     dup public-key gcd nip 1 = [
         rot drop
     ] [
diff --git a/extra/crypto/sha1/sha1.factor b/extra/crypto/sha1/sha1.factor
index af3671e7d9..8f3d3e6ecc 100755
--- a/extra/crypto/sha1/sha1.factor
+++ b/extra/crypto/sha1/sha1.factor
@@ -124,5 +124,5 @@ SYMBOLS: h0 h1 h2 h3 h4 A B C D E w K ;
 : byte-array>sha1-interleave ( string -- seq )
     [ zero? ] left-trim
     dup length odd? [ 1 tail ] when
-    seq>2seq [ byte-array>sha1 ] 2apply
+    seq>2seq [ byte-array>sha1 ] bi@
     swap 2seq>seq ;
diff --git a/extra/documents/documents.factor b/extra/documents/documents.factor
index 60ae592d4c..14f0dc41ac 100755
--- a/extra/documents/documents.factor
+++ b/extra/documents/documents.factor
@@ -12,7 +12,7 @@ IN: documents
 
 : =line ( n loc -- newloc ) second 2array ;
 
-: lines-equal? ( loc1 loc2 -- ? ) [ first ] 2apply number= ;
+: lines-equal? ( loc1 loc2 -- ? ) [ first ] bi@ number= ;
 
 TUPLE: document locs ;
 
@@ -46,7 +46,7 @@ TUPLE: document locs ;
     2over = [
         3drop
     ] [
-        >r [ first ] 2apply 1+ dup <slice> r> each
+        >r [ first ] bi@ 1+ dup <slice> r> each
     ] if ; inline
 
 : start/end-on-line ( from to line# -- n1 n2 )
@@ -85,7 +85,7 @@ TUPLE: document locs ;
 
 : (set-doc-range) ( newlines from to lines -- )
     [ prepare-insert ] 3keep
-    >r [ first ] 2apply 1+ r>
+    >r [ first ] bi@ 1+ r>
     replace-slice ;
 
 : set-doc-range ( string from to document -- )
diff --git a/extra/faq/faq.factor b/extra/faq/faq.factor
index d7624466f7..c6d9cd04d2 100644
--- a/extra/faq/faq.factor
+++ b/extra/faq/faq.factor
@@ -91,7 +91,7 @@ C: <faq> faq
 : faq-sections, ( question-lists -- )
     unclip question-list-seq length 1+ dupd
     [ question-list-seq length + ] accumulate nip
-    0 -rot [ pick question-list>html [ , nl, ] 2apply 1+ ] 2each drop ;
+    0 -rot [ pick question-list>html [ , nl, ] bi@ 1+ ] 2each drop ;
 
 : faq>html ( faq -- div )
     "div" [
diff --git a/extra/fry/fry-docs.factor b/extra/fry/fry-docs.factor
index 739e7d012c..84d02d529d 100755
--- a/extra/fry/fry-docs.factor
+++ b/extra/fry/fry-docs.factor
@@ -69,7 +69,7 @@ $nl
     { { $link curry } { $snippet ": curry '[ , @ ] ;" } }
     { { $link with } { $snippet ": with swapd '[ , _ @ ] ;" } }
     { { $link compose } { $snippet ": compose '[ @ @ ] ;" } }
-    { { $link 2apply } { $snippet ": 2apply tuck '[ , @ , @ ] call ;" } }
+    { { $link bi@ } { $snippet ": bi@ tuck '[ , @ , @ ] call ;" } }
 } ;
 
 ARTICLE: "fry.philosophy" "Fried quotation philosophy"
diff --git a/extra/help/lint/lint.factor b/extra/help/lint/lint.factor
index b65e44fda4..01e08473c6 100755
--- a/extra/help/lint/lint.factor
+++ b/extra/help/lint/lint.factor
@@ -59,7 +59,7 @@ IN: help.lint
 
 : check-see-also ( word element -- )
     nip \ $see-also swap elements [
-        1 tail dup prune [ length ] 2apply assert=
+        1 tail dup prune [ length ] bi@ assert=
     ] each ;
 
 : vocab-exists? ( name -- ? )
diff --git a/extra/http/http.factor b/extra/http/http.factor
index 69c0ba2c9f..6ff4829b48 100755
--- a/extra/http/http.factor
+++ b/extra/http/http.factor
@@ -106,7 +106,7 @@ IN: http
 : query>assoc ( query -- assoc )
     dup [
         "&" split [
-            "=" split1 [ dup [ url-decode ] when ] 2apply
+            "=" split1 [ dup [ url-decode ] when ] bi@
         ] H{ } map>assoc
     ] when ;
 
diff --git a/extra/icfp/2006/2006.factor b/extra/icfp/2006/2006.factor
index 1740e8a523..e88301c7f8 100755
--- a/extra/icfp/2006/2006.factor
+++ b/extra/icfp/2006/2006.factor
@@ -51,14 +51,14 @@ SYMBOL: open-arrays
 
 : binary-op ( quot -- ? )
     >r get-cba r>
-    swap >r >r [ reg-val ] 2apply swap r> call r>
+    swap >r >r [ reg-val ] bi@ swap r> call r>
     set-reg f ; inline
 
 : op1 ( opcode -- ? )
     [ swap arr-val ] binary-op ;
 
 : op2 ( opcode -- ? )
-    get-cba >r [ reg-val ] 2apply r> reg-val set-arr f ;
+    get-cba >r [ reg-val ] bi@ r> reg-val set-arr f ;
 
 : op3 ( opcode -- ? )
     [ + >32bit ] binary-op ;
diff --git a/extra/inverse/inverse.factor b/extra/inverse/inverse.factor
index d524180471..1b7badd94a 100755
--- a/extra/inverse/inverse.factor
+++ b/extra/inverse/inverse.factor
@@ -151,10 +151,10 @@ MACRO: undo ( quot -- ) [undo] ;
 \ - [ + ] [ - ] define-math-inverse
 \ * [ / ] [ / ] define-math-inverse
 \ / [ * ] [ / ] define-math-inverse
-\ ^ [ recip ^ ] [ [ log ] 2apply / ] define-math-inverse
+\ ^ [ recip ^ ] [ [ log ] bi@ / ] define-math-inverse
 
 \ ? 2 [
-    [ assert-literal ] 2apply
+    [ assert-literal ] bi@
     [ swap >r over = r> swap [ 2drop f ] [ = [ t ] [ fail ] if ] if ]
     2curry
 ] define-pop-inverse
diff --git a/extra/io/encodings/utf16/utf16.factor b/extra/io/encodings/utf16/utf16.factor
index e8ca04af35..fbc296e57c 100755
--- a/extra/io/encodings/utf16/utf16.factor
+++ b/extra/io/encodings/utf16/utf16.factor
@@ -78,7 +78,7 @@ M: utf16le decode-char
     swap BIN: 11111111 bitand ;
 
 : stream-write2 ( stream char1 char2 -- )
-    rot [ stream-write1 ] curry 2apply ;
+    rot [ stream-write1 ] curry bi@ ;
 
 : char>utf16be ( stream char -- )
     dup HEX: FFFF > [
diff --git a/extra/io/nonblocking/nonblocking.factor b/extra/io/nonblocking/nonblocking.factor
index b345a98e88..85319ad8ef 100755
--- a/extra/io/nonblocking/nonblocking.factor
+++ b/extra/io/nonblocking/nonblocking.factor
@@ -161,5 +161,5 @@ TUPLE: datagram-port addr packet packet-addr ;
 
 : check-datagram-send ( packet addrspec port -- )
     dup check-datagram-port
-    datagram-port-addr [ class ] 2apply assert=
+    datagram-port-addr [ class ] bi@ assert=
     class byte-array assert= ;
diff --git a/extra/io/sockets/impl/impl.factor b/extra/io/sockets/impl/impl.factor
index 77e8e098b1..8480fcd856 100755
--- a/extra/io/sockets/impl/impl.factor
+++ b/extra/io/sockets/impl/impl.factor
@@ -64,8 +64,8 @@ M: inet6 inet-ntop ( data addrspec -- str )
 
 M: inet6 inet-pton ( str addrspec -- data )
     drop "::" split1
-    [ [ ":" split [ hex> dup 0 ? ] map ] [ f ] if* ] 2apply
-    2dup [ length ] 2apply + 8 swap - 0 <array> swap 3append
+    [ [ ":" split [ hex> dup 0 ? ] map ] [ f ] if* ] bi@
+    2dup [ length ] bi@ + 8 swap - 0 <array> swap 3append
     [ 2 >be ] map concat >byte-array ;
 
 M: inet6 address-size drop 16 ;
diff --git a/extra/io/unix/files/files.factor b/extra/io/unix/files/files.factor
index 3b493d2fe4..b0b0ba456a 100755
--- a/extra/io/unix/files/files.factor
+++ b/extra/io/unix/files/files.factor
@@ -49,7 +49,7 @@ M: unix-io touch-file ( path -- )
     close ;
 
 M: unix-io move-file ( from to -- )
-    [ normalize-pathname ] 2apply rename io-error ;
+    [ normalize-pathname ] bi@ rename io-error ;
 
 M: unix-io delete-file ( path -- )
     normalize-pathname unlink io-error ;
@@ -69,7 +69,7 @@ M: unix-io delete-directory ( path -- )
     ] with-disposal ;
 
 M: unix-io copy-file ( from to -- )
-    [ normalize-pathname ] 2apply
+    [ normalize-pathname ] bi@
     [ (copy-file) ]
     [ swap file-info file-info-permissions chmod io-error ]
     2bi ;
diff --git a/extra/io/windows/ce/backend/backend.factor b/extra/io/windows/ce/backend/backend.factor
index f51521dfcc..152e76a6c7 100755
--- a/extra/io/windows/ce/backend/backend.factor
+++ b/extra/io/windows/ce/backend/backend.factor
@@ -46,5 +46,5 @@ M: windows-ce-io (init-stdio) ( -- )
             1 _getstdfilex _fileno
             2 _getstdfilex _fileno
         ] if [ f <win32-file> ] 3apply
-        rot <reader> -rot [ <writer> ] 2apply
+        rot <reader> -rot [ <writer> ] bi@
     ] with-variable ;
diff --git a/extra/io/windows/windows.factor b/extra/io/windows/windows.factor
index 64c4684e15..27917cedfa 100755
--- a/extra/io/windows/windows.factor
+++ b/extra/io/windows/windows.factor
@@ -135,14 +135,14 @@ M: windows-io (file-appender) ( path -- stream )
     open-append <win32-file> <writer> ;
 
 M: windows-io move-file ( from to -- )
-    [ normalize-pathname ] 2apply MoveFile win32-error=0/f ;
+    [ normalize-pathname ] bi@ MoveFile win32-error=0/f ;
 
 M: windows-io delete-file ( path -- )
     normalize-pathname DeleteFile win32-error=0/f ;
 
 M: windows-io copy-file ( from to -- )
     dup parent-directory make-directories
-    [ normalize-pathname ] 2apply 0 CopyFile win32-error=0/f ;
+    [ normalize-pathname ] bi@ 0 CopyFile win32-error=0/f ;
 
 M: windows-io make-directory ( path -- )
     normalize-pathname
diff --git a/extra/jamshred/tunnel/tunnel.factor b/extra/jamshred/tunnel/tunnel.factor
index 61fef7959c..7be406d37a 100755
--- a/extra/jamshred/tunnel/tunnel.factor
+++ b/extra/jamshred/tunnel/tunnel.factor
@@ -72,7 +72,7 @@ TUPLE: segment number color radius ;
 : sub-tunnel ( from to sements -- segments )
     #! return segments between from and to, after clamping from and to to
     #! valid values
-    [ sequence-index-range [ clamp-to-range ] curry 2apply ] keep <slice> ;
+    [ sequence-index-range [ clamp-to-range ] curry bi@ ] keep <slice> ;
 
 : nearer-segment ( segment segment oint -- segment )
     #! return whichever of the two segments is nearer to the oint
diff --git a/extra/koszul/koszul.factor b/extra/koszul/koszul.factor
index 71cbb1d951..f286690d37 100755
--- a/extra/koszul/koszul.factor
+++ b/extra/koszul/koszul.factor
@@ -57,7 +57,7 @@ SYMBOL: terms
     terms get [ [ swap +@ ] assoc-each ] bind ;
 
 : alt+ ( x y -- x+y )
-    [ >alt ] 2apply [ (alt+) (alt+) ] with-terms ;
+    [ >alt ] bi@ [ (alt+) (alt+) ] with-terms ;
 
 ! Multiplication
 : alt*n ( vec n -- vec )
@@ -79,7 +79,7 @@ SYMBOL: terms
     ] curry each ;
 
 : duplicates? ( seq -- ? )
-    dup prune [ length ] 2apply > ;
+    dup prune [ length ] bi@ > ;
 
 : (wedge) ( n basis1 basis2 -- n basis )
     append dup duplicates? [
@@ -90,7 +90,7 @@ SYMBOL: terms
     ] if ;
 
 : wedge ( x y -- x.y )
-    [ >alt ] 2apply [
+    [ >alt ] bi@ [
         swap [
             [
                 2swap [
@@ -200,7 +200,7 @@ DEFER: (d)
     ] with map ;
 
 : bigraded-betti ( u-generators z-generators -- seq )
-    [ basis graded ] 2apply tensor bigraded-ker/im-d
+    [ basis graded ] bi@ tensor bigraded-ker/im-d
     [ [ [ first ] map ] map ] keep
     [ [ second ] map 2 head* { 0 0 } prepend ] map
     1 tail dup first length 0 <array> add
@@ -278,7 +278,7 @@ DEFER: (d)
     ] with map ;
 
 : bigraded-laplacian ( u-generators z-generators quot -- seq )
-    >r [ basis graded ] 2apply tensor bigraded-triples r>
+    >r [ basis graded ] bi@ tensor bigraded-triples r>
     [ [ first3 ] swap compose map ] curry map ; inline
 
 : bigraded-laplacian-betti ( u-generators z-generators -- seq )
diff --git a/extra/lazy-lists/lazy-lists.factor b/extra/lazy-lists/lazy-lists.factor
index 07cd34b4df..52cca64b2f 100644
--- a/extra/lazy-lists/lazy-lists.factor
+++ b/extra/lazy-lists/lazy-lists.factor
@@ -52,7 +52,7 @@ M: cons nil? ( cons -- bool )
 TUPLE: lazy-cons car cdr ;
 
 : lazy-cons ( car cdr -- promise )
-    [ promise ] 2apply \ lazy-cons construct-boa
+    [ promise ] bi@ \ lazy-cons construct-boa
     T{ promise f f t f } clone
     [ set-promise-value ] keep ;
 
diff --git a/extra/levenshtein/levenshtein.factor b/extra/levenshtein/levenshtein.factor
index 07e16fb862..98b376593c 100644
--- a/extra/levenshtein/levenshtein.factor
+++ b/extra/levenshtein/levenshtein.factor
@@ -17,7 +17,7 @@ SYMBOL: d
 SYMBOL: costs
 
 : init-d ( str1 str2 -- )
-    [ length 1+ ] 2apply 2dup <matrix> d set
+    [ length 1+ ] bi@ 2dup <matrix> d set
     [ 0 over ->d ] each
     [ dup 0 ->d ] each ; inline
 
@@ -39,7 +39,7 @@ SYMBOL: costs
     [
         2dup init-d
         2dup compute-costs
-        [ length ] 2apply [
+        [ length ] bi@ [
             [ levenshtein-step ] curry each
         ] with each
         levenshtein-result
diff --git a/extra/lint/lint.factor b/extra/lint/lint.factor
index a220eece01..dcf52f723a 100644
--- a/extra/lint/lint.factor
+++ b/extra/lint/lint.factor
@@ -71,7 +71,7 @@ def-hash get-global [
 
 ! Remove set-alien-cell, etc.
 [
-    drop [ accessor-words swap seq-diff ] keep [ length ] 2apply =
+    drop [ accessor-words swap seq-diff ] keep [ length ] bi@ =
 ] assoc-subset
 
 ! Remove trivial defs
@@ -148,7 +148,7 @@ GENERIC: run-lint ( obj -- obj )
 : filter-symbols ( alist -- alist )
     [
         nip first dup def-hash get at
-        [ first ] 2apply literalize = not
+        [ first ] bi@ literalize = not
     ] assoc-subset ;
 
 M: sequence run-lint ( seq -- seq )
diff --git a/extra/match/match.factor b/extra/match/match.factor
index fef925431d..2c6923a6ba 100755
--- a/extra/match/match.factor
+++ b/extra/match/match.factor
@@ -32,10 +32,10 @@ SYMBOL: _
         { [ 2dup = ] [ 2drop t ] }
         { [ 2dup [ _ eq? ] either? ] [ 2drop t ] }
         { [ 2dup [ sequence? ] both? ] [
-            2dup [ length ] 2apply =
+            2dup [ length ] bi@ =
             [ [ (match) ] 2all? ] [ 2drop f ] if ] }
         { [ 2dup [ tuple? ] both? ]
-          [ [ tuple>array ] 2apply [ (match) ] 2all? ] }
+          [ [ tuple>array ] bi@ [ (match) ] 2all? ] }
         { [ t ] [ 2drop f ] }
     } cond ;
 
diff --git a/extra/math/complex/complex.factor b/extra/math/complex/complex.factor
index 236d9df7a0..588f34d3fc 100755
--- a/extra/math/complex/complex.factor
+++ b/extra/math/complex/complex.factor
@@ -8,11 +8,11 @@ math.functions.private sequences parser ;
 M: real real-part ;
 M: real imaginary-part drop 0 ;
 
-M: complex absq >rect [ sq ] 2apply + ;
+M: complex absq >rect [ sq ] bi@ + ;
 
 : 2>rect ( x y -- xr yr xi yi )
-    [ [ real-part ] 2apply ] 2keep
-    [ imaginary-part ] 2apply ; inline
+    [ [ real-part ] bi@ ] 2keep
+    [ imaginary-part ] bi@ ; inline
 
 M: complex number=
     2>rect number= [ number= ] [ 2drop f ] if ;
diff --git a/extra/math/functions/functions.factor b/extra/math/functions/functions.factor
index 85e07fe73f..dcbccb4316 100755
--- a/extra/math/functions/functions.factor
+++ b/extra/math/functions/functions.factor
@@ -101,7 +101,7 @@ M: real absq sq ;
     >r - abs r> < ;
 
 : ~rel ( x y epsilon -- ? )
-    >r [ - abs ] 2keep [ abs ] 2apply + r> * < ;
+    >r [ - abs ] 2keep [ abs ] bi@ + r> * < ;
 
 : ~ ( x y epsilon -- ? )
     {
@@ -124,7 +124,7 @@ M: real absq sq ;
 : arg ( z -- arg ) >float-rect swap fatan2 ; inline
 
 : >polar ( z -- abs arg )
-    >float-rect [ [ sq ] 2apply + fsqrt ] 2keep swap fatan2 ;
+    >float-rect [ [ sq ] bi@ + fsqrt ] 2keep swap fatan2 ;
     inline
 
 : cis ( arg -- z ) dup fcos swap fsin rect> ; inline
diff --git a/extra/math/polynomials/polynomials.factor b/extra/math/polynomials/polynomials.factor
index 000d97f2a6..d6ac71e629 100644
--- a/extra/math/polynomials/polynomials.factor
+++ b/extra/math/polynomials/polynomials.factor
@@ -13,10 +13,10 @@ IN: math.polynomials
 <PRIVATE
 : 2pad-left ( p p n -- p p ) 0 [ pad-left swap ] 2keep pad-left swap ;
 : 2pad-right ( p p n -- p p ) 0 [ pad-right swap ] 2keep pad-right swap ;
-: pextend ( p p -- p p ) 2dup [ length ] 2apply max 2pad-right ;
-: pextend-left ( p p -- p p ) 2dup [ length ] 2apply max 2pad-left ;
+: pextend ( p p -- p p ) 2dup [ length ] bi@ max 2pad-right ;
+: pextend-left ( p p -- p p ) 2dup [ length ] bi@ max 2pad-left ;
 : unempty ( seq -- seq ) dup empty? [ drop { 0 } ] when ;
-: 2unempty ( seq seq -- seq seq ) [ unempty ] 2apply ;
+: 2unempty ( seq seq -- seq seq ) [ unempty ] bi@ ;
 
 PRIVATE>
 : p= ( p p -- ? ) pextend = ;
@@ -24,7 +24,7 @@ PRIVATE>
 : ptrim ( p -- p )
     dup singleton? [ [ zero? ] right-trim ] unless ;
 
-: 2ptrim ( p p -- p p ) [ ptrim ] 2apply ;
+: 2ptrim ( p p -- p p ) [ ptrim ] bi@ ;
 : p+ ( p p -- p ) pextend v+ ;
 : p- ( p p -- p ) pextend v- ;
 : n*p ( n p -- n*p ) n*v ;
@@ -32,7 +32,7 @@ PRIVATE>
 ! convolution
 : pextend-conv ( p p -- p p )
     #! extend to: p_m + p_n - 1 
-    2dup [ length ] 2apply + 1- 2pad-right [ >vector ] 2apply ;
+    2dup [ length ] bi@ + 1- 2pad-right [ >vector ] bi@ ;
 
 : p* ( p p -- p )
     #! Multiply two polynomials.
@@ -46,13 +46,13 @@ PRIVATE>
 
 : p/mod-setup ( p p -- p p n )
     2ptrim
-    2dup [ length ] 2apply -
+    2dup [ length ] bi@ -
     dup 1 < [ drop 1 ] when
     [ over length + 0 pad-left pextend ] keep 1+ ;
 
 : /-last ( seq seq -- a )
     #! divide the last two numbers in the sequences
-    [ peek ] 2apply / ;
+    [ peek ] bi@ / ;
 
 : (p/mod)
     2dup /-last
@@ -74,7 +74,7 @@ PRIVATE>
     ] if ;
 
 : pgcd ( p p -- p q )
-    swap V{ 0 } clone V{ 1 } clone 2swap (pgcd) [ >array ] 2apply ;
+    swap V{ 0 } clone V{ 1 } clone 2swap (pgcd) [ >array ] bi@ ;
 
 : pdiff ( p -- p' )
     #! Polynomial derivative.
diff --git a/extra/math/quaternions/quaternions.factor b/extra/math/quaternions/quaternions.factor
index d61afd17c3..f121e4a0d1 100755
--- a/extra/math/quaternions/quaternions.factor
+++ b/extra/math/quaternions/quaternions.factor
@@ -14,7 +14,7 @@ IN: math.quaternions
 
 : ** conjugate * ; inline
 
-: 2q ( u v -- u' u'' v' v'' ) [ first2 ] 2apply ; inline
+: 2q ( u v -- u' u'' v' v'' ) [ first2 ] bi@ ; inline
 
 : q*a ( u v -- a ) 2q swapd ** >r * r> - ; inline
 
diff --git a/extra/math/ratios/ratios.factor b/extra/math/ratios/ratios.factor
index 5d07bd046f..3c430111ff 100755
--- a/extra/math/ratios/ratios.factor
+++ b/extra/math/ratios/ratios.factor
@@ -7,7 +7,7 @@ USING: kernel kernel.private math math.functions math.private ;
     dup numerator swap denominator ; inline
 
 : 2>fraction ( a/b c/d -- a c b d )
-    [ >fraction ] 2apply swapd ; inline
+    [ >fraction ] bi@ swapd ; inline
 
 <PRIVATE
 
@@ -26,7 +26,7 @@ M: integer /
     dup zero? [
         "Division by zero" throw
     ] [
-        dup 0 < [ [ neg ] 2apply ] when
+        dup 0 < [ [ neg ] bi@ ] when
         2dup gcd nip tuck /i >r /i r> fraction>
     ] if ;
 
diff --git a/extra/math/statistics/statistics.factor b/extra/math/statistics/statistics.factor
index 4c60363be0..f7295604cd 100644
--- a/extra/math/statistics/statistics.factor
+++ b/extra/math/statistics/statistics.factor
@@ -46,13 +46,13 @@ IN: math.statistics
 
 : ((r)) ( mean(x) mean(y) {x} {y} -- (r) )
     ! finds sigma((xi-mean(x))(yi-mean(y))
-    0 [ [ >r pick r> swap - ] 2apply * + ] 2reduce 2nip ;
+    0 [ [ >r pick r> swap - ] bi@ * + ] 2reduce 2nip ;
 
 : (r) ( mean(x) mean(y) {x} {y} sx sy -- r )
     * recip >r [ ((r)) ] keep length 1- / r> * ;
 
 : [r] ( {{x,y}...} -- mean(x) mean(y) {x} {y} sx sy )
-    first2 [ [ [ mean ] 2apply ] 2keep ] 2keep [ std ] 2apply ;
+    first2 [ [ [ mean ] bi@ ] 2keep ] 2keep [ std ] bi@ ;
 
 : r ( {{x,y}...} -- r )
     [r] (r) ;
diff --git a/extra/maze/maze.factor b/extra/maze/maze.factor
index 14a493cec5..5d7bb9a1a2 100644
--- a/extra/maze/maze.factor
+++ b/extra/maze/maze.factor
@@ -22,7 +22,7 @@ SYMBOL: visited
 : random-neighbour ( cell -- newcell ) choices random ;
 
 : vertex ( pair -- )
-    first2 [ 0.5 + line-width * ] 2apply glVertex2d ;
+    first2 [ 0.5 + line-width * ] bi@ glVertex2d ;
 
 : (draw-maze) ( cell -- )
     dup vertex
diff --git a/extra/money/money.factor b/extra/money/money.factor
index 4058ee9e6a..4584daf592 100644
--- a/extra/money/money.factor
+++ b/extra/money/money.factor
@@ -23,9 +23,9 @@ TUPLE: not-a-decimal ;
 : parse-decimal ( str -- ratio )
     "." split1
     >r dup "-" head? [ drop t "0" ] [ f swap ] if r>
-    [ dup empty? [ drop "0" ] when ] 2apply
+    [ dup empty? [ drop "0" ] when ] bi@
     dup length
-    >r [ string>number dup [ not-a-decimal ] unless ] 2apply r>
+    >r [ string>number dup [ not-a-decimal ] unless ] bi@ r>
     10 swap ^ / + swap [ neg ] when ;
 
 : DECIMAL:
diff --git a/extra/multi-methods/multi-methods.factor b/extra/multi-methods/multi-methods.factor
index ed82d2478e..ac62fb08f9 100755
--- a/extra/multi-methods/multi-methods.factor
+++ b/extra/multi-methods/multi-methods.factor
@@ -113,7 +113,7 @@ TUPLE: no-method arguments generic ;
     ] curry assoc-map ;
 
 : sorted-methods ( alist -- alist' )
-    [ [ first ] 2apply classes< ] topological-sort ;
+    [ [ first ] bi@ classes< ] topological-sort ;
 
 : niceify-method [ dup \ f eq? [ drop f ] when ] map ;
 
diff --git a/extra/opengl/demo-support/demo-support.factor b/extra/opengl/demo-support/demo-support.factor
index 61d3be0e15..84515305c8 100755
--- a/extra/opengl/demo-support/demo-support.factor
+++ b/extra/opengl/demo-support/demo-support.factor
@@ -38,7 +38,7 @@ M: demo-gadget pref-dim* ( gadget -- dim )
 
 : demo-gadget-frustum ( -- -x x -y y near far )
     FOV-RATIO NEAR-PLANE FOV / v*n
-    first2 [ -+ ] 2apply NEAR-PLANE FAR-PLANE ;
+    first2 [ -+ ] bi@ NEAR-PLANE FAR-PLANE ;
 
 : demo-gadget-set-matrices ( gadget -- )
     GL_PROJECTION glMatrixMode
diff --git a/extra/opengl/opengl.factor b/extra/opengl/opengl.factor
index 08e3cb204b..36d24e1300 100755
--- a/extra/opengl/opengl.factor
+++ b/extra/opengl/opengl.factor
@@ -8,9 +8,9 @@ math.parser opengl.gl opengl.glu combinators arrays sequences
 splitting words byte-arrays assocs combinators.lib ;
 IN: opengl
 
-: coordinates [ first2 ] 2apply ;
+: coordinates [ first2 ] bi@ ;
 
-: fix-coordinates [ first2 [ >fixnum ] 2apply ] 2apply ;
+: fix-coordinates [ first2 [ >fixnum ] bi@ ] bi@ ;
 
 : gl-color ( color -- ) first4 glColor4d ; inline
 
@@ -85,7 +85,7 @@ MACRO: all-enabled-client-state ( seq quot -- )
 
 : unit-circle dup [ sin ] map swap [ cos ] map ;
 
-: adjust-points [ [ 1 + 0.5 * ] map ] 2apply ;
+: adjust-points [ [ 1 + 0.5 * ] map ] bi@ ;
 
 : scale-points 2array flip [ v* ] with map [ v+ ] with map ;
 
diff --git a/extra/parser-combinators/parser-combinators.factor b/extra/parser-combinators/parser-combinators.factor
index bf06708e09..d6aacf9645 100755
--- a/extra/parser-combinators/parser-combinators.factor
+++ b/extra/parser-combinators/parser-combinators.factor
@@ -35,7 +35,7 @@ C: <parse-result> parse-result
     ] if ;
 
 : string= ( str1 str2 ignore-case -- ? )
-    [ [ >upper ] 2apply ] when sequence= ;
+    [ [ >upper ] bi@ ] when sequence= ;
 
 : string-head? ( str head ignore-case -- ? )
     2over shorter? [
@@ -327,7 +327,7 @@ LAZY: <(+)> ( parser -- parser )
     nonempty-list-of { } succeed <|> ;
 
 LAZY: surrounded-by ( parser start end -- parser' )
-    [ token ] 2apply swapd pack ;
+    [ token ] bi@ swapd pack ;
 
 : exactly-n ( parser n -- parser' )
     swap <repetition> <and-parser> [ flatten ] <@ ;
diff --git a/extra/peg/parsers/parsers.factor b/extra/peg/parsers/parsers.factor
index 7a82418c27..49035ea43c 100755
--- a/extra/peg/parsers/parsers.factor
+++ b/extra/peg/parsers/parsers.factor
@@ -70,7 +70,7 @@ MEMO: pack ( begin body end -- parser )
   >r >r hide r> r> hide 3seq [ first ] action ;
 
 : surrounded-by ( parser begin end -- parser' )
-  [ token ] 2apply swapd pack ;
+  [ token ] bi@ swapd pack ;
 
 : 'digit' ( -- parser )
   [ digit? ] satisfy [ digit> ] action ;
diff --git a/extra/peg/peg.factor b/extra/peg/peg.factor
index 247a64eac2..d6d573da79 100755
--- a/extra/peg/peg.factor
+++ b/extra/peg/peg.factor
@@ -11,7 +11,7 @@ USE: prettyprint
 TUPLE: parse-result remaining ast ;
 
 TUPLE: parser id compiled ;
-M: parser equal? [ id>> ] 2apply = ;
+M: parser equal? [ id>> ] bi@ = ;
 C: <parser> parser
 
 SYMBOL: ignore 
diff --git a/extra/project-euler/009/009.factor b/extra/project-euler/009/009.factor
index f09643d290..690fed9012 100644
--- a/extra/project-euler/009/009.factor
+++ b/extra/project-euler/009/009.factor
@@ -31,7 +31,7 @@ IN: project-euler.009
 : abc ( p q -- triplet )
     [
         2dup * ,                    ! a = p * q
-        [ sq ] 2apply 2dup - 2 / ,  ! b = (p² - q²) / 2
+        [ sq ] bi@ 2dup - 2 / ,  ! b = (p² - q²) / 2
         + 2 / ,                     ! c = (p² + q²) / 2
     ] { } make natural-sort ;
 
diff --git a/extra/project-euler/014/014.factor b/extra/project-euler/014/014.factor
index 02c5dbb9d3..32b1aa5549 100644
--- a/extra/project-euler/014/014.factor
+++ b/extra/project-euler/014/014.factor
@@ -39,7 +39,7 @@ IN: project-euler.014
     dup even? [ 2 / ] [ 3 * 1+ ] if ;
 
 : longest ( seq seq -- seq )
-    2dup [ length ] 2apply > [ drop ] [ nip ] if ;
+    2dup [ length ] bi@ > [ drop ] [ nip ] if ;
 
 PRIVATE>
 
diff --git a/extra/project-euler/026/026.factor b/extra/project-euler/026/026.factor
index 3ad1908aa6..f1f546ec1c 100644
--- a/extra/project-euler/026/026.factor
+++ b/extra/project-euler/026/026.factor
@@ -58,7 +58,7 @@ PRIVATE>
 
 : max-period ( seq -- elt n )
     dup [ period-length ] map dup supremum
-    over index [ swap nth ] curry 2apply ;
+    over index [ swap nth ] curry bi@ ;
 
 PRIVATE>
 
diff --git a/extra/project-euler/027/027.factor b/extra/project-euler/027/027.factor
index 2bc7894684..2d99204bf3 100644
--- a/extra/project-euler/027/027.factor
+++ b/extra/project-euler/027/027.factor
@@ -60,7 +60,7 @@ IN: project-euler.027
 
 : max-consecutive ( seq -- elt n )
     dup [ first2 consecutive-primes ] map dup supremum
-    over index [ swap nth ] curry 2apply ;
+    over index [ swap nth ] curry bi@ ;
 
 PRIVATE>
 
diff --git a/extra/project-euler/033/033.factor b/extra/project-euler/033/033.factor
index 6f29c3519e..35b1c87e7a 100644
--- a/extra/project-euler/033/033.factor
+++ b/extra/project-euler/033/033.factor
@@ -33,10 +33,10 @@ IN: project-euler.033
     10 99 [a,b] dup cartesian-product [ first2 < ] subset ;
 
 : safe? ( ax xb -- ? )
-    [ 10 /mod ] 2apply -roll = rot zero? not and nip ;
+    [ 10 /mod ] bi@ -roll = rot zero? not and nip ;
 
 : ax/xb ( ax xb -- z/f )
-    2dup safe? [ [ 10 /mod ] 2apply 2nip / ] [ 2drop f ] if ;
+    2dup safe? [ [ 10 /mod ] bi@ 2nip / ] [ 2drop f ] if ;
 
 : curious? ( m n -- ? )
     2dup / [ ax/xb ] dip = ;
diff --git a/extra/project-euler/044/044.factor b/extra/project-euler/044/044.factor
index 62e516e4b0..bc8aec8bde 100644
--- a/extra/project-euler/044/044.factor
+++ b/extra/project-euler/044/044.factor
@@ -31,7 +31,7 @@ IN: project-euler.044
     dup 3 * 1- * 2 / ;
 
 : sum-and-diff? ( m n -- ? )
-    2dup + -rot - [ pentagonal? ] 2apply and ;
+    2dup + -rot - [ pentagonal? ] bi@ and ;
 
 PRIVATE>
 
diff --git a/extra/project-euler/079/079.factor b/extra/project-euler/079/079.factor
index 30c46de0a0..b4cbd6dbcb 100644
--- a/extra/project-euler/079/079.factor
+++ b/extra/project-euler/079/079.factor
@@ -35,7 +35,7 @@ IN: project-euler.079
     ] { } make ;
 
 : find-source ( seq -- elt )
-    dup values swap keys [ prune ] 2apply seq-diff
+    dup values swap keys [ prune ] bi@ seq-diff
     dup empty? [ "Topological sort failed" throw ] [ first ] if ;
 
 : remove-source ( seq elt -- seq )
diff --git a/extra/random-tester/random/random.factor b/extra/random-tester/random/random.factor
index 163de69a59..11f2e60d1a 100755
--- a/extra/random-tester/random/random.factor
+++ b/extra/random-tester/random/random.factor
@@ -54,7 +54,7 @@ IN: random-tester
     ] if ;
 
 : random-ratio ( -- ratio )
-    1000000000 dup [ random ] 2apply 1+ / 50% [ neg ] when dup [ drop random-ratio ] unless 10% [ drop 0 ] when ;
+    1000000000 dup [ random ] bi@ 1+ / 50% [ neg ] when dup [ drop random-ratio ] unless 10% [ drop 0 ] when ;
 
 : random-float ( -- float )
     50% [ random-ratio ] [ special-floats get random ] if
diff --git a/extra/regexp/regexp.factor b/extra/regexp/regexp.factor
index b57724d1db..fa36a7c6f8 100755
--- a/extra/regexp/regexp.factor
+++ b/extra/regexp/regexp.factor
@@ -16,7 +16,7 @@ SYMBOL: ignore-case?
 
 : char-between?-quot ( ch1 ch2 -- quot )
     ignore-case? get
-    [ [ ch>upper ] 2apply [ >r >r ch>upper r> r> between? ] ]
+    [ [ ch>upper ] bi@ [ >r >r ch>upper r> r> between? ] ]
     [ [ between? ] ]
     if 2curry ;
 
diff --git a/extra/regexp2/regexp2.factor b/extra/regexp2/regexp2.factor
index e62eb76cb1..1f2bbde171 100644
--- a/extra/regexp2/regexp2.factor
+++ b/extra/regexp2/regexp2.factor
@@ -16,7 +16,7 @@ SYMBOL: ignore-case?
     
 : char-between?-quot ( ch1 ch2 -- quot )
     ignore-case? get
-    [ [ ch>upper ] 2apply [ >r >r ch>upper r> r> between? ] ]
+    [ [ ch>upper ] bi@ [ >r >r ch>upper r> r> between? ] ]
     [ [ between? ] ]
     if 2curry ;
     
diff --git a/extra/reports/noise/noise.factor b/extra/reports/noise/noise.factor
index 2614a774dd..7e9496c90d 100755
--- a/extra/reports/noise/noise.factor
+++ b/extra/reports/noise/noise.factor
@@ -9,7 +9,7 @@ IN: reports.noise
         { -nrot 5 }
         { -roll 4 }
         { -rot 3 }
-        { 2apply 1 }
+        { bi@ 1 }
         { 2curry 1 }
         { 2drop 1 }
         { 2dup 1 }
diff --git a/extra/roman/roman.factor b/extra/roman/roman.factor
index 7466883c5f..a3e61dd889 100644
--- a/extra/roman/roman.factor
+++ b/extra/roman/roman.factor
@@ -23,7 +23,7 @@ TUPLE: roman-range-error n ;
     ] if ;
 
 : roman<= ( ch1 ch2 -- ? )
-    [ 1string roman-digits index ] 2apply >= ;
+    [ 1string roman-digits index ] bi@ >= ;
 
 : roman>n ( ch -- n )
     1string roman-digits index roman-values nth ;
@@ -57,7 +57,7 @@ PRIVATE>
 <PRIVATE
 
 : 2roman> ( str1 str2 -- m n )
-    [ roman> ] 2apply ;
+    [ roman> ] bi@ ;
 
 : binary-roman-op ( str1 str2 quot -- str3 )
     >r 2roman> r> call >roman ; inline
diff --git a/extra/semantic-db/semantic-db-tests.factor b/extra/semantic-db/semantic-db-tests.factor
index 257133c67f..c523053740 100644
--- a/extra/semantic-db/semantic-db-tests.factor
+++ b/extra/semantic-db/semantic-db-tests.factor
@@ -60,7 +60,7 @@ test-db [
         "charlie" create-node* "charlie" set
         "gertrude" create-node* "gertrude" set
         [ t ] [ "adam" get "bob" get parent-child* integer? ] unit-test
-        { { "eve" "bob" } { "eve" "fran" } { "bob" "gertrude" } { "bob" "fran" } { "fran" "charlie" } } [ first2 [ get ] 2apply parent-child ] each
+        { { "eve" "bob" } { "eve" "fran" } { "bob" "gertrude" } { "bob" "fran" } { "fran" "charlie" } } [ first2 [ get ] bi@ parent-child ] each
         [ { "bob" "fran" } ] [ "eve" get children [ node-content ] map ] unit-test
         [ { "adam" "eve" } ] [ "bob" get parents [ node-content ] map ] unit-test
         [ "fran" { "charlie" } ] [ "fran" get get-node-hierarchy dup tree-id node-content swap tree-children [ tree-id node-content ] map ] unit-test
diff --git a/extra/serialize/serialize.factor b/extra/serialize/serialize.factor
index 2865b1fd6c..ac247057f4 100755
--- a/extra/serialize/serialize.factor
+++ b/extra/serialize/serialize.factor
@@ -24,7 +24,7 @@ C: <id> id
 
 M: id hashcode* obj>> hashcode* ;
 
-M: id equal? over id? [ [ obj>> ] 2apply eq? ] [ 2drop f ] if ;
+M: id equal? over id? [ [ obj>> ] bi@ eq? ] [ 2drop f ] if ;
 
 : add-object ( obj -- )
     #! Add an object to the sequence of already serialized
diff --git a/extra/shufflers/shufflers.factor b/extra/shufflers/shufflers.factor
index 172db1def1..b11668a53e 100644
--- a/extra/shufflers/shufflers.factor
+++ b/extra/shufflers/shufflers.factor
@@ -20,7 +20,7 @@ IN: shufflers
 
 : put-effect ( word -- )
     dup word-name "-" split1
-    [ >array [ 1string ] map ] 2apply
+    [ >array [ 1string ] map ] bi@
     <effect> "declared-effect" set-word-prop ;
 
 : in-shuffle ( -- ) in get ".shuffle" append set-in ;
diff --git a/extra/sudoku/sudoku.factor b/extra/sudoku/sudoku.factor
index db5fb75617..764c4d92f0 100644
--- a/extra/sudoku/sudoku.factor
+++ b/extra/sudoku/sudoku.factor
@@ -18,7 +18,7 @@ SYMBOL: board
 : cell-contains? ( n x y i -- ? ) 3 /mod pair+ board> = ;
 
 : box-contains? ( n x y -- ? )
-    [ 3 /i 3 * ] 2apply
+    [ 3 /i 3 * ] bi@
     9 [ >r 3dup r> cell-contains? ] contains?
     >r 3drop r> ;
 
diff --git a/extra/tar/tar.factor b/extra/tar/tar.factor
index d1c4b148a5..99af06b80f 100755
--- a/extra/tar/tar.factor
+++ b/extra/tar/tar.factor
@@ -35,7 +35,7 @@ linkname magic version uname gname devmajor devminor prefix ;
 
 : header-checksum ( seq -- x )
     148 cut-slice 8 tail-slice
-    [ sum ] 2apply + 256 + ;
+    [ sum ] bi@ + 256 + ;
 
 TUPLE: checksum-error ;
 TUPLE: malformed-block-error ;
diff --git a/extra/tools/completion/completion.factor b/extra/tools/completion/completion.factor
index e44c3c401e..16bde2100f 100755
--- a/extra/tools/completion/completion.factor
+++ b/extra/tools/completion/completion.factor
@@ -40,7 +40,7 @@ unicode.categories ;
 
 : score ( full fuzzy -- n )
     dup [
-        [ [ length ] 2apply - 15 swap [-] 3 /f ] 2keep
+        [ [ length ] bi@ - 15 swap [-] 3 /f ] 2keep
         runs [
             [ 0 [ pick score-1 max ] reduce nip ] keep
             length * +
@@ -57,7 +57,7 @@ unicode.categories ;
 
 : complete ( full short -- score )
     [ dupd fuzzy score ] 2keep
-    [ <reversed> ] 2apply
+    [ <reversed> ] bi@
     dupd fuzzy score max ;
 
 : completion ( short candidate -- result )
diff --git a/extra/tools/deploy/shaker/strip-cocoa.factor b/extra/tools/deploy/shaker/strip-cocoa.factor
index b37e42f323..de8f8740f0 100755
--- a/extra/tools/deploy/shaker/strip-cocoa.factor
+++ b/extra/tools/deploy/shaker/strip-cocoa.factor
@@ -14,7 +14,7 @@ global [
 
     sent-messages get
     super-sent-messages get
-    [ keys [ objc-methods get at dup ] H{ } map>assoc ] 2apply
+    [ keys [ objc-methods get at dup ] H{ } map>assoc ] bi@
     super-message-senders [ intersect ] change
     message-senders [ intersect ] change
 
diff --git a/extra/ui/gadgets/borders/borders.factor b/extra/ui/gadgets/borders/borders.factor
index e58ba343c7..6b548aaf68 100644
--- a/extra/ui/gadgets/borders/borders.factor
+++ b/extra/ui/gadgets/borders/borders.factor
@@ -24,7 +24,7 @@ M: border pref-dim*
     <rect> ;
 
 : scale-rect ( rect vec -- loc dim )
-    [ v* ] curry >r rect-bounds r> 2apply ;
+    [ v* ] curry >r rect-bounds r> bi@ ;
 
 : average-rects ( rect1 rect2 weight -- rect )
     tuck >r >r scale-rect r> r> { 1 1 } swap v- scale-rect
diff --git a/extra/ui/gadgets/editors/editors.factor b/extra/ui/gadgets/editors/editors.factor
index def6b99b05..b3ecad6aed 100755
--- a/extra/ui/gadgets/editors/editors.factor
+++ b/extra/ui/gadgets/editors/editors.factor
@@ -135,7 +135,7 @@ M: editor ungraft*
         dup editor-caret-color gl-color
         dup caret-loc origin get v+
         swap caret-dim over v+
-        [ { 0.5 -0.5 } v+ ] 2apply gl-line
+        [ { 0.5 -0.5 } v+ ] bi@ gl-line
     ] when ;
 
 : line-translation ( n -- loc )
diff --git a/extra/ui/gadgets/gadgets.factor b/extra/ui/gadgets/gadgets.factor
index 267f6f0f0f..ddcaa4b979 100755
--- a/extra/ui/gadgets/gadgets.factor
+++ b/extra/ui/gadgets/gadgets.factor
@@ -22,7 +22,7 @@ M: array rect-dim drop { 0 0 } ;
 : rect-extent ( rect -- loc ext ) rect-bounds over v+ ;
 
 : 2rect-extent ( rect rect -- loc1 loc2 ext1 ext2 )
-    [ rect-extent ] 2apply swapd ;
+    [ rect-extent ] bi@ swapd ;
 
 : <extent-rect> ( loc ext -- rect ) over [v-] <rect> ;
 
diff --git a/extra/ui/gadgets/grids/grids-tests.factor b/extra/ui/gadgets/grids/grids-tests.factor
index 0792d55135..f20275ff25 100644
--- a/extra/ui/gadgets/grids/grids-tests.factor
+++ b/extra/ui/gadgets/grids/grids-tests.factor
@@ -25,13 +25,13 @@ IN: ui.gadgets.grids.tests
 [ { 100 200 } ] [
     100x100
     100x100
-    [ 1array ] 2apply 2array <grid> pref-dim
+    [ 1array ] bi@ 2array <grid> pref-dim
 ] unit-test
 
 [ ] [
     100x100
     100x100
-    [ 1array ] 2apply 2array <grid> layout
+    [ 1array ] bi@ 2array <grid> layout
 ] unit-test
 
 [ { 230 120 } { 100 100 } { 100 100 } ] [
diff --git a/extra/ui/gadgets/scrollers/scrollers.factor b/extra/ui/gadgets/scrollers/scrollers.factor
index 99bd1be876..d4a1895894 100755
--- a/extra/ui/gadgets/scrollers/scrollers.factor
+++ b/extra/ui/gadgets/scrollers/scrollers.factor
@@ -57,7 +57,7 @@ scroller H{
     2dup control-value = [ 2drop ] [ set-control-value ] if ;
 
 : rect-min ( rect1 rect2 -- rect )
-    >r [ rect-loc ] keep r> [ rect-dim ] 2apply vmin <rect> ;
+    >r [ rect-loc ] keep r> [ rect-dim ] bi@ vmin <rect> ;
 
 : (scroll>rect) ( rect scroller -- )
     [
diff --git a/extra/unicode/breaks/breaks.factor b/extra/unicode/breaks/breaks.factor
index dfc7bf2264..4c8c6491ca 100644
--- a/extra/unicode/breaks/breaks.factor
+++ b/extra/unicode/breaks/breaks.factor
@@ -26,7 +26,7 @@ CATEGORY: grapheme-control Zl Zp Cc Cf ;
 : process-other-extend ( lines -- set )
     [ "#" split1 drop ";" split1 drop trim-blank ] map
     [ empty? not ] subset
-    [ ".." split1 [ dup ] unless* [ hex> ] 2apply [a,b] ] map
+    [ ".." split1 [ dup ] unless* [ hex> ] bi@ [a,b] ] map
     concat >set ;
 
 : other-extend-lines ( -- lines )
@@ -83,7 +83,7 @@ VALUE: grapheme-table
     grapheme-table nth nth not ;
 
 : chars ( i str n -- str[i] str[i+n] )
-    swap >r dupd + r> [ ?nth ] curry 2apply ;
+    swap >r dupd + r> [ ?nth ] curry bi@ ;
 
 : find-index ( seq quot -- i ) find drop ; inline
 : find-last-index ( seq quot -- i ) find-last drop ; inline
diff --git a/extra/unicode/case/case.factor b/extra/unicode/case/case.factor
index 8129ec17f8..092a247204 100755
--- a/extra/unicode/case/case.factor
+++ b/extra/unicode/case/case.factor
@@ -100,7 +100,7 @@ SYMBOL: locale ! Just casing locale, or overall?
     >upper >lower ;
 
 : insensitive= ( str1 str2 -- ? )
-    [ >case-fold ] 2apply = ;
+    [ >case-fold ] bi@ = ;
 
 : lower? ( string -- ? )
     dup >lower = ;
diff --git a/extra/unicode/normalize/normalize.factor b/extra/unicode/normalize/normalize.factor
index 47637e8330..d62beb1a2c 100644
--- a/extra/unicode/normalize/normalize.factor
+++ b/extra/unicode/normalize/normalize.factor
@@ -38,7 +38,7 @@ IN: unicode.normalize
 
 : (insert) ( seq n quot -- )
     over 0 = [ 3drop ] [
-        [ >r dup 1- rot [ nth ] curry 2apply r> 2apply > ] 3keep
+        [ >r dup 1- rot [ nth ] curry bi@ r> bi@ > ] 3keep
         roll [ 3drop ]
         [ >r [ dup 1- rot exchange ] 2keep 1- r> (insert) ] if
     ] if ; inline
diff --git a/extra/units/units.factor b/extra/units/units.factor
index b92cbb659a..cf53ceaee3 100755
--- a/extra/units/units.factor
+++ b/extra/units/units.factor
@@ -16,7 +16,7 @@ M: dimensions-not-equal summary drop "Dimensions do not match" ;
     1array split1 append ;
 
 : 2remove-one ( seq seq obj -- seq seq )
-    [ remove-one ] curry 2apply ;
+    [ remove-one ] curry bi@ ;
 
 : symbolic-reduce ( seq seq -- seq seq )
     2dup seq-intersect dup empty?
@@ -24,7 +24,7 @@ M: dimensions-not-equal summary drop "Dimensions do not match" ;
 
 : <dimensioned> ( n top bot -- obj )
     symbolic-reduce
-    [ natural-sort ] 2apply
+    [ natural-sort ] bi@
     dimensioned construct-boa ;
 
 : >dimensioned< ( d -- n top bot )
@@ -37,10 +37,10 @@ M: dimensions-not-equal summary drop "Dimensions do not match" ;
     { dimensioned-top dimensioned-bot } get-slots ;
 
 : check-dimensions ( d d -- )
-    [ dimensions 2array ] 2apply =
+    [ dimensions 2array ] bi@ =
     [ dimensions-not-equal ] unless ;
 
-: 2values [ dimensioned-value ] 2apply ;
+: 2values [ dimensioned-value ] bi@ ;
 
 : <dimension-op
     2dup check-dimensions dup dimensions 2swap 2values ;
@@ -56,9 +56,9 @@ M: dimensions-not-equal summary drop "Dimensions do not match" ;
     { } { } <dimensioned> ;
 
 : d* ( d d -- d )
-    [ dup number? [ scalar ] when ] 2apply
-    [ [ dimensioned-top ] 2apply append ] 2keep
-    [ [ dimensioned-bot ] 2apply append ] 2keep
+    [ dup number? [ scalar ] when ] bi@
+    [ [ dimensioned-top ] bi@ append ] 2keep
+    [ [ dimensioned-bot ] bi@ append ] 2keep
     2values * dimension-op> ;
 
 : d-neg ( d -- d ) -1 d* ;
diff --git a/extra/xmode/catalog/catalog.factor b/extra/xmode/catalog/catalog.factor
index c7eaafe887..822b290f88 100755
--- a/extra/xmode/catalog/catalog.factor
+++ b/extra/xmode/catalog/catalog.factor
@@ -63,7 +63,7 @@ SYMBOL: rule-sets
     over [ dupd update ] [ nip clone ] if ;
 
 : import-keywords ( parent child -- )
-    over >r [ rule-set-keywords ] 2apply ?update
+    over >r [ rule-set-keywords ] bi@ ?update
     r> set-rule-set-keywords ;
 
 : import-rules ( parent child -- )