diff --git a/extra/modern/modern-tests.factor b/extra/modern/modern-tests.factor
new file mode 100644
index 0000000000..ff71231544
--- /dev/null
+++ b/extra/modern/modern-tests.factor
@@ -0,0 +1,243 @@
+! Copyright (C) 2017 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: modern modern.slices multiline tools.test ;
+IN: modern.tests
+
+{ f } [ "" upper-colon? ] unit-test
+{ t } [ ":" upper-colon? ] unit-test
+{ t } [ "::" upper-colon? ] unit-test
+{ t } [ ":::" upper-colon? ] unit-test
+{ t } [ "FOO:" upper-colon? ] unit-test
+{ t } [ "FOO::" upper-colon? ] unit-test
+{ t } [ "FOO:::" upper-colon? ] unit-test
+
+! 'FOO:
+{ f } [ "'" upper-colon? ] unit-test
+{ t } [ "':" upper-colon? ] unit-test
+{ t } [ "'::" upper-colon? ] unit-test
+{ t } [ "':::" upper-colon? ] unit-test
+{ t } [ "'FOO:" upper-colon? ] unit-test
+{ t } [ "'FOO::" upper-colon? ] unit-test
+{ t } [ "'FOO:::" upper-colon? ] unit-test
+
+! \FOO: is not an upper-colon form, it is deactivated by the \
+{ f } [ "\\" upper-colon? ] unit-test
+{ f } [ "\\:" upper-colon? ] unit-test
+{ f } [ "\\::" upper-colon? ] unit-test
+{ f } [ "\\:::" upper-colon? ] unit-test
+{ f } [ "\\FOO:" upper-colon? ] unit-test
+{ f } [ "\\FOO::" upper-colon? ] unit-test
+{ f } [ "\\FOO:::" upper-colon? ] unit-test
+
+
+! Comment
+{
+    { { "!" "" } }
+} [ "!" string>literals >strings ] unit-test
+
+{
+    { { "!" " lol" } }
+} [ "! lol" string>literals >strings ] unit-test
+
+{
+    { "lol!" }
+} [ "lol!" string>literals >strings ] unit-test
+
+{
+    { { "!" "lol" } }
+} [ "!lol" string>literals >strings ] unit-test
+
+! Colon
+{
+    { ":asdf:" }
+} [ ":asdf:" string>literals >strings ] unit-test
+
+{
+    { { "one:" { "1" } } }
+} [ "one: 1" string>literals >strings ] unit-test
+
+{
+    { { "two::" { "1" "2" } } }
+} [ "two:: 1 2" string>literals >strings ] unit-test
+
+{
+    { "1" ":>" "one" }
+} [ "1 :> one" string>literals >strings ] unit-test
+
+{
+    { { ":" { "foo" } ";" } }
+} [ ": foo ;" string>literals >strings ] unit-test
+
+{
+    {
+        { "FOO:" { "a" } }
+        { "BAR:" { "b" } }
+    }
+} [ "FOO: a BAR: b" string>literals >strings ] unit-test
+
+{
+    { { "FOO:" { "a" } ";" } }
+} [ "FOO: a ;" string>literals >strings ] unit-test
+
+{
+    { { "FOO:" { "a" } "FOO;" } }
+} [ "FOO: a FOO;" string>literals >strings ] unit-test
+
+
+! Acute
+{
+    { { "<A" { } "A>" } }
+} [ "<A A>" string>literals >strings ] unit-test
+
+{
+    { { "<B:" { "hi" } ";B>" } }
+} [ "<B: hi ;B>" string>literals >strings ] unit-test
+
+{ { "<foo>" } } [ "<foo>" string>literals >strings ] unit-test
+{ { ">foo<" } } [ ">foo<" string>literals >strings ] unit-test
+
+{ { "foo>" } } [ "foo>" string>literals >strings ] unit-test
+{ { ">foo" } } [ ">foo" string>literals >strings ] unit-test
+{ { ">foo>" } } [ ">foo>" string>literals >strings ] unit-test
+{ { ">>foo>" } } [ ">>foo>" string>literals >strings ] unit-test
+{ { ">>foo>>" } } [ ">>foo>>" string>literals >strings ] unit-test
+
+{ { "foo<" } } [ "foo<" string>literals >strings ] unit-test
+{ { "<foo" } } [ "<foo" string>literals >strings ] unit-test
+{ { "<foo<" } } [ "<foo<" string>literals >strings ] unit-test
+{ { "<<foo<" } } [ "<<foo<" string>literals >strings ] unit-test
+{ { "<<foo<<" } } [ "<<foo<<" string>literals >strings ] unit-test
+
+! Backslash \AVL{ foo\bar foo\bar{
+{
+    { { "SYNTAX:" { "\\AVL{" } } }
+} [ "SYNTAX: \\AVL{" string>literals >strings ] unit-test
+
+[ "\\" string>literals >strings ] must-fail ! \ alone should be legal eventually (?)
+
+{ { "\\FOO" } } [ "\\FOO" string>literals >strings ] unit-test
+
+{
+    { "foo\\bar" }
+} [ "foo\\bar" string>literals >strings ] unit-test
+
+[ "foo\\bar{" string>literals >strings ] must-fail
+
+{
+    { { "foo\\bar{" { "1" } "}" } }
+} [ "foo\\bar{ 1 }" string>literals >strings ] unit-test
+
+{ { { "char:" { "\\{" } } } } [ "char: \\{" string>literals >strings ] unit-test
+[ "char: {" string>literals >strings ] must-fail
+[ "char: [" string>literals >strings ] must-fail
+[ "char: {" string>literals >strings ] must-fail
+[ "char: \"" string>literals >strings ] must-fail
+! { { { "char:" { "\\\\" } } } } [ "char: \\\\" string>literals >strings ] unit-test
+
+[ "char: \\" string>literals >strings ] must-fail ! char: \ should be legal eventually
+
+{ { { "\\" { "(" } } } } [ "\\ (" string>literals >strings ] unit-test
+
+{ { "\\[[" } } [ "\\[[" string>literals >strings ] unit-test
+{ { "\\[=[" } } [ "\\[=[" string>literals >strings ] unit-test
+{ { "\\[==[" } } [ "\\[==[" string>literals >strings ] unit-test
+
+
+{ t } [ "FOO:" strict-upper? ] unit-test
+{ t } [ ":" strict-upper? ] unit-test
+{ f } [ "<FOO" strict-upper? ] unit-test
+{ f } [ "<FOO:" strict-upper? ] unit-test
+{ f } [ "->" strict-upper? ] unit-test
+{ f } [ "FOO>" strict-upper? ] unit-test
+{ f } [ ";FOO>" strict-upper? ] unit-test
+
+{ f } [ "FOO" section-open? ] unit-test
+{ f } [ "FOO:" section-open? ] unit-test
+{ f } [ ";FOO" section-close? ] unit-test
+{ f } [ "FOO" section-close? ] unit-test
+
+
+! Strings
+{
+    { { "url\"" "google.com" "\"" } }
+} [ [[ url"google.com" ]] string>literals >strings ] unit-test
+
+{
+    { { "\"" "google.com" "\"" } }
+} [ [[ "google.com" ]] string>literals >strings ] unit-test
+
+{
+    {
+        { "(" { "a" "b" } ")" }
+        { "[" { "a" "b" "+" } "]" }
+        { "(" { "c" } ")" }
+    }
+} [ "( a b ) [ a b + ] ( c )" string>literals >strings ] unit-test
+
+![[
+! Concatenated syntax
+{
+    {
+        {
+            { "(" { "a" "b" } ")" }
+            { "[" { "a" "b" "+" } "]" }
+            { "(" { "c" } ")" }
+        }
+    }
+} [ "( a b )[ a b + ]( c )" string>literals >strings ] unit-test
+
+{
+    {
+        {
+            { "\"" "abc" "\"" }
+            { "[" { "0" } "]" }
+        }
+    }
+} [ "\"abc\"[ 0 ]" string>literals >strings ] unit-test
+]]
+
+
+{
+    {
+        { "<FOO" { { "BAR:" { "bar" } } } "FOO>" }
+    }
+} [ "<FOO BAR: bar FOO>" string>literals >strings ] unit-test
+
+{
+    {
+        { "<FOO:" { "foo" { "BAR:" { "bar" } } } ";FOO>" }
+    }
+} [ "<FOO: foo BAR: bar ;FOO>" string>literals >strings ] unit-test
+
+
+![[
+{
+    {
+        {
+            {
+                "foo::"
+                {
+                    {
+                        { "<FOO" { } "FOO>" }
+                        { "[" { "0" } "]" }
+                        { "[" { "1" } "]" }
+                        { "[" { "2" } "]" }
+                        { "[" { "3" } "]" }
+                    }
+                    { { "<BAR" { } "BAR>" } }
+                }
+            }
+        }
+    }
+} [ "foo:: <FOO FOO>[ 0 ][ 1 ][ 2 ][ 3 ] <BAR BAR>" string>literals >strings ] unit-test
+]]
+
+{
+    {
+        { "foo::" { { "<FOO" { } "FOO>" } { "[" { "0" } "]" } } }
+        { "[" { "1" } "]" }
+        { "[" { "2" } "]" }
+        { "[" { "3" } "]" }
+        { "<BAR" { } "BAR>" }
+    }
+} [ "foo:: <FOO FOO> [ 0 ] [ 1 ] [ 2 ] [ 3 ] <BAR BAR>" string>literals >strings ] unit-test
diff --git a/extra/modern/modern.factor b/extra/modern/modern.factor
new file mode 100644
index 0000000000..63f2645eda
--- /dev/null
+++ b/extra/modern/modern.factor
@@ -0,0 +1,499 @@
+! Copyright (C) 2016 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: arrays assocs combinators combinators.short-circuit
+continuations fry io.encodings.utf8 io.files kernel locals make
+math math.order modern.paths modern.slices sequences
+sequences.extras sets splitting strings unicode vocabs.loader ;
+IN: modern
+
+ERROR: string-expected-got-eof n string ;
+ERROR: long-opening-mismatch tag open n string ch ;
+
+! (( )) [[ ]] {{ }}
+MACRO:: read-double-matched ( open-ch -- quot: ( n string tag ch -- n' string seq ) )
+    open-ch dup matching-delimiter {
+        [ drop 2 swap <string> ]
+        [ drop 1string ]
+        [ nip 2 swap <string> ]
+    } 2cleave :> ( openstr2 openstr1 closestr2 )
+    [| n string tag! ch |
+        ch {
+            { CHAR: = [
+                tag 1 cut-slice* drop tag! ! tag of (=( is ( here, fix it
+                n string openstr1 slice-til-separator-inclusive [ -1 modify-from ] dip :> ( n' string' opening ch )
+                ch open-ch = [ tag openstr2 n string ch long-opening-mismatch ] unless
+                opening matching-delimiter-string :> needle
+
+                n' string' needle slice-til-string :> ( n'' string'' payload closing )
+                n'' string
+                tag opening payload closing 4array
+            ] }
+            { open-ch [
+                tag 1 cut-slice* swap tag! 1 modify-to :> opening
+                n 1 + string closestr2 slice-til-string :> ( n' string' payload closing )
+                n' string
+                tag opening payload closing 4array
+            ] }
+            [ [ tag openstr2 n string ] dip long-opening-mismatch ]
+        } case
+     ] ;
+
+: read-double-matched-paren ( n string tag ch -- n' string seq ) CHAR: ( read-double-matched ;
+: read-double-matched-bracket ( n string tag ch -- n' string seq ) CHAR: [ read-double-matched ;
+: read-double-matched-brace ( n string tag ch -- n' string seq ) CHAR: { read-double-matched ;
+
+DEFER: lex-factor-top
+DEFER: lex-factor
+ERROR: lex-expected-but-got-eof n string expected ;
+! For implementing [ { (
+: lex-until ( n string tag-sequence -- n' string payload )
+    3dup '[
+        [
+            lex-factor-top dup f like [ , ] when* [
+                dup [
+                    ! } gets a chance, but then also full seq { } after recursion...
+                    [ _ ] dip '[ _ sequence= ] any? not
+                ] [
+                    drop t ! loop again?
+                ] if
+            ] [
+                _ _ _ lex-expected-but-got-eof
+            ] if*
+        ] loop
+    ] { } make ;
+
+DEFER: section-close?
+DEFER: upper-colon?
+DEFER: lex-factor-nested
+: lex-colon-until ( n string tag-sequence -- n' string payload )
+    '[
+        [
+            lex-factor-nested dup f like [ , ] when* [
+                dup [
+                    ! This is for ending COLON: forms like ``A: PRIVATE>``
+                    dup section-close? [
+                        drop f
+                    ] [
+                        ! } gets a chance, but then also full seq { } after recursion...
+                        [ _ ] dip '[ _ sequence= ] any? not
+                    ] if
+                ] [
+                    drop t ! loop again?
+                ] if
+            ] [
+                f
+            ] if*
+        ] loop
+    ] { } make ;
+
+: split-double-dash ( seq -- seqs )
+    dup [ { [ "--" sequence= ] } 1&& ] split-when
+    dup length 1 > [ nip ] [ drop ] if ;
+
+MACRO:: read-matched ( ch -- quot: ( n string tag -- n' string slice' ) )
+    ch dup matching-delimiter {
+        [ drop "=" swap prefix ]
+        [ nip 1string ]
+    } 2cleave :> ( openstreq closestr1 )  ! [= ]
+    [| n string tag |
+        n string tag
+        2over nth-check-eof {
+            { [ dup openstreq member? ] [ ch read-double-matched ] } ! (=( or ((
+            { [ dup blank? ] [
+                drop dup '[ _ matching-delimiter-string closestr1 2array members lex-until ] dip
+                swap unclip-last 3array ] } ! ( foo )
+            [ drop [ slice-til-whitespace drop ] dip span-slices ]  ! (foo)
+        } cond
+    ] ;
+
+: read-bracket ( n string slice -- n' string slice' ) CHAR: [ read-matched ;
+: read-brace ( n string slice -- n' string slice' ) CHAR: { read-matched ;
+: read-paren ( n string slice -- n' string slice' ) CHAR: ( read-matched ;
+: read-string-payload ( n string -- n' string )
+    over [
+        { CHAR: \\ CHAR: \" } slice-til-separator-inclusive {
+            { f [ drop ] }
+            { CHAR: \" [ drop ] }
+            { CHAR: \\ [ drop next-char-from drop read-string-payload ] }
+        } case
+    ] [
+        string-expected-got-eof
+    ] if ;
+
+:: read-string ( n string tag -- n' string seq )
+    n string read-string-payload drop :> n'
+    n' string
+    n' [ n string string-expected-got-eof ] unless
+    n n' 1 - string <slice>
+    n' 1 - n' string <slice>
+    tag -rot 3array ;
+
+: take-comment ( n string slice -- n' string comment )
+    2over ?nth CHAR: [ = [
+        [ 1 + ] 2dip 2over ?nth read-double-matched-bracket
+    ] [
+        [ slice-til-eol drop ] dip swap 2array
+    ] if ;
+
+: terminator? ( slice -- ? )
+    {
+        [ ";" sequence= ]
+        [ "]" sequence= ]
+        [ "}" sequence= ]
+        [ ")" sequence= ]
+    } 1|| ;
+
+ERROR: expected-length-tokens n string length seq ;
+: ensure-no-false ( n string seq -- n string seq )
+    dup [ length 0 > ] all? [ [ length ] keep expected-length-tokens ] unless ;
+
+ERROR: token-expected n string obj ;
+ERROR: unexpected-terminator n string slice ;
+: read-lowercase-colon ( n string slice -- n' string lowercase-colon )
+    dup [ CHAR: : = ] count-tail
+    '[
+        _ [ lex-factor ] replicate ensure-no-false dup [ token-expected ] unless
+        dup terminator? [ unexpected-terminator ] when
+    ] dip swap 2array ;
+
+: (strict-upper?) ( string -- ? )
+    {
+        ! All chars must...
+        [
+            [
+                { [ CHAR: A CHAR: Z between? ] [ "':-\\#" member? ] } 1||
+            ] all?
+        ]
+        ! At least one char must...
+        [ [ { [ CHAR: A CHAR: Z between? ] [ CHAR: ' = ] } 1|| ] any? ]
+    } 1&& ;
+
+: strict-upper? ( string -- ? )
+    { [ ":" sequence= ] [ (strict-upper?) ] } 1|| ;
+
+! <A <A: but not <A>
+: section-open? ( string -- ? )
+    {
+        [ "<" head? ]
+        [ length 2 >= ]
+        [ rest strict-upper? ]
+        [ ">" tail? not ]
+    } 1&& ;
+
+: html-self-close? ( string -- ? )
+    {
+        [ "<" head? ]
+        [ length 2 >= ]
+        [ rest strict-upper? not ]
+        [ [ blank? ] any? not ]
+        [ "/>" tail? ]
+    } 1&& ;
+
+: html-full-open? ( string -- ? )
+    {
+        [ "<" head? ]
+        [ length 2 >= ]
+        [ second CHAR: / = not ]
+        [ rest strict-upper? not ]
+        [ [ blank? ] any? not ]
+        [ ">" tail? ]
+    } 1&& ;
+
+: html-half-open? ( string -- ? )
+    {
+        [ "<" head? ]
+        [ length 2 >= ]
+        [ second CHAR: / = not ]
+        [ rest strict-upper? not ]
+        [ [ blank? ] any? not ]
+        [ ">" tail? not ]
+    } 1&& ;
+
+: html-close? ( string -- ? )
+    {
+        [ "</" head? ]
+        [ length 2 >= ]
+        [ rest strict-upper? not ]
+        [ [ blank? ] any? not ]
+        [ ">" tail? ]
+    } 1&& ;
+
+: special-acute? ( string -- ? )
+    {
+        [ section-open? ]
+        [ html-self-close? ]
+        [ html-full-open? ]
+        [ html-half-open? ]
+        [ html-close? ]
+    } 1|| ;
+
+: upper-colon? ( string -- ? )
+    dup { [ length 0 > ] [ [ CHAR: : = ] all? ] } 1&& [
+        drop t
+    ] [
+        {
+            [ length 2 >= ]
+            [ "\\" head? not ] ! XXX: good?
+            [ ":" tail? ]
+            [ dup [ CHAR: : = ] find drop head strict-upper? ]
+        } 1&&
+    ] if ;
+
+: section-close? ( string -- ? )
+    {
+        [ length 2 >= ]
+        [ "\\" head? not ] ! XXX: good?
+        [ ">" tail? ]
+        [
+            {
+                [ but-last strict-upper? ]
+                [ { [ ";" head? ] [ rest but-last strict-upper? ] } 1&& ]
+            } 1||
+        ]
+    } 1&& ;
+
+: read-til-semicolon ( n string slice -- n' string semi )
+    dup '[ but-last ";" append ";" 2array { "--" ")" } append lex-colon-until ] dip
+    swap
+    ! What ended the FOO: .. ; form?
+    ! Remove the ; from the payload if present
+    ! XXX: probably can remove this, T: is dumb
+    ! Also in stack effects ( T: int -- ) can be ended by -- and )
+    dup ?last {
+        { [ dup ";" sequence= ] [ drop unclip-last 3array ] }
+        { [ dup ";" tail? ] [ drop unclip-last 3array ] }
+        { [ dup "--" sequence= ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] }
+        { [ dup "]" sequence= ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] }
+        { [ dup "}" sequence= ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] }
+        { [ dup ")" sequence= ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] } ! (n*quot) breaks
+        { [ dup section-close? ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] }
+        { [ dup upper-colon? ] [ drop unclip-last -rot 2array [ rewind-slice ] dip ] }
+        [ drop 2array ]
+    } cond ;
+
+ERROR: colon-word-must-be-all-uppercase-or-lowercase n string word ;
+: read-colon ( n string slice -- n' string colon )
+    {
+        { [ dup strict-upper? ] [ read-til-semicolon ] }
+        { [ dup ":" tail? ] [ dup ":" head? [ read-lowercase-colon ] unless ] } ! :foo: vs foo:
+        [ ]
+    } cond ;
+
+: read-acute-html ( n string slice -- n' string acute )
+    {
+        ! <FOO <FOO:
+        { [ dup section-open? ] [
+            [
+                matching-section-delimiter 1array lex-until
+            ] keep swap unclip-last 3array
+        ] }
+        ! <foo/>
+        { [ dup html-self-close? ] [
+            ! do nothing special
+        ] }
+        ! <foo>
+        { [ dup html-full-open? ] [
+            dup [
+                rest-slice
+                dup ">" tail? [ but-last-slice ] when
+                "</" ">" surround 1array lex-until unclip-last
+            ] dip -rot 3array
+        ] }
+        ! <foo
+        { [ dup html-half-open? ] [
+            ! n seq slice
+            [ { ">" "/>" } lex-until ] dip
+            ! n seq slice2 slice
+            over ">" sequence= [
+                "</" ">" surround array '[ _ lex-until ] dip unclip-last
+                -rot roll unclip-last [ 3array ] 2dip 3array
+            ] [
+                ! self-contained
+                swap unclip-last 3array
+            ] if
+        ] }
+        ! </foo>
+        { [ dup html-close? ] [
+            ! Do nothing
+        ] }
+        [ [ slice-til-whitespace drop ] dip span-slices ]
+    } cond ;
+
+: read-acute ( n string slice -- n' string acute )
+    [ matching-section-delimiter 1array lex-until ] keep swap unclip-last 3array ;
+
+! Words like append! and suffix! are allowed for now.
+: read-exclamation ( n string slice -- n' string obj )
+    dup { [ "!" sequence= ] [ "#!" sequence= ] } 1||
+    [ take-comment ] [ merge-slice-til-whitespace ] if ;
+
+ERROR: no-backslash-payload n string slice ;
+: (read-backslash) ( n string slice -- n' string obj )
+    merge-slice-til-whitespace dup "\\" tail? [
+        ! \ foo, M\ foo
+        dup [ CHAR: \\ = ] count-tail
+        '[
+            _ [ skip-blank-from slice-til-whitespace drop ] replicate
+            ensure-no-false
+            dup [ no-backslash-payload ] unless
+        ] dip swap 2array
+    ] when ;
+
+DEFER: lex-factor-top*
+: read-backslash ( n string slice -- n' string obj )
+    ! foo\ so far, could be foo\bar{
+    ! remove the \ and continue til delimiter/eof
+    [ "\"!:[{(<>\s\r\n" slice-til-either ] dip swap [ span-slices ] dip
+    over "\\" head? [
+        drop
+        ! \ foo
+        dup [ CHAR: \\ = ] all? [ (read-backslash) ] [ merge-slice-til-whitespace ] if
+    ] [
+        ! foo\ or foo\bar (?)
+        over "\\" tail? [ drop (read-backslash) ] [ lex-factor-top* ] if
+    ] if ;
+
+! If the slice is 0 width, we stopped on whitespace.
+! Advance the index and read again!
+
+: read-token-or-whitespace-top ( n string slice -- n' string slice/f )
+    dup length 0 = [ [ 1 + ] 2dip drop lex-factor-top ] when ;
+
+: read-token-or-whitespace-nested ( n string slice -- n' string slice/f )
+    dup length 0 = [ [ 1 + ] 2dip drop lex-factor-nested ] when ;
+
+: lex-factor-fallthrough ( n/f string slice/f ch/f -- n'/f string literal )
+    {
+        { CHAR: \ [ read-backslash ] }
+        { CHAR: [ [ read-bracket ] }
+        { CHAR: { [ read-brace ] }
+        { CHAR: ( [ read-paren ] }
+        { CHAR: ] [ ] }
+        { CHAR: } [ ] }
+        { CHAR: ) [ ] }
+        { CHAR: " [ read-string ] }
+        { CHAR: ! [ read-exclamation ] }
+        { CHAR: > [
+            [ [ CHAR: > = not ] slice-until ] dip merge-slices
+            dup section-close? [
+                [ slice-til-whitespace drop ] dip ?span-slices
+            ] unless
+        ] }
+        { f [ ] }
+    } case ;
+
+! Inside a FOO: or a <FOO FOO>
+: lex-factor-nested* ( n/f string slice/f ch/f -- n'/f string literal )
+    {
+        ! Nested ``A: a B: b`` so rewind and let the parser get it top-level
+        { CHAR: : [
+            ! A: B: then interrupt the current parser
+            ! A: b: then keep going
+            merge-slice-til-whitespace
+            dup { [ upper-colon? ] [ ":" = ] } 1||
+            ! dup upper-colon?
+            [ rewind-slice f ]
+            [ read-colon ] if
+        ] }
+        { CHAR: < [
+            ! FOO: a b <BAR: ;BAR>
+            ! FOO: a b <BAR BAR>
+            ! FOO: a b <asdf>
+            ! FOO: a b <asdf asdf>
+
+            ! if we are in a FOO: and we hit a <BAR or <BAR:
+            ! then end the FOO:
+            ! Don't rewind for a <foo/> or <foo></foo>
+            [ slice-til-whitespace drop ] dip span-slices
+            dup section-open? [ rewind-slice f ] when
+        ] }
+        { CHAR: \s [ read-token-or-whitespace-nested ] }
+        { CHAR: \r [ read-token-or-whitespace-nested ] }
+        { CHAR: \n [ read-token-or-whitespace-nested ] }
+        [ lex-factor-fallthrough ]
+    } case ;
+
+: lex-factor-nested ( n/f string -- n'/f string literal )
+    ! skip-whitespace
+    "\"\\!:[{(]})<>\s\r\n" slice-til-either
+    lex-factor-nested* ; inline
+
+: lex-factor-top* ( n/f string slice/f ch/f -- n'/f string literal )
+    {
+        { CHAR: : [ merge-slice-til-whitespace read-colon ] }
+        { CHAR: < [
+            ! FOO: a b <BAR: ;BAR>
+            ! FOO: a b <BAR BAR>
+            ! FOO: a b <asdf>
+            ! FOO: a b <asdf asdf>
+
+            ! if we are in a FOO: and we hit a <BAR or <BAR:
+            ! then end the FOO:
+            [ slice-til-whitespace drop ] dip span-slices
+            ! read-acute-html
+            dup section-open? [ read-acute ] when
+        ] }
+
+        { CHAR: \s [ read-token-or-whitespace-top ] }
+        { CHAR: \r [ read-token-or-whitespace-top ] }
+        { CHAR: \n [ read-token-or-whitespace-top ] }
+        [ lex-factor-fallthrough ]
+    } case ;
+
+: lex-factor-top ( n/f string -- n'/f string literal )
+    ! skip-whitespace
+    "\"\\!:[{(]})<>\s\r\n" slice-til-either
+    lex-factor-top* ; inline
+
+ERROR: compound-syntax-disallowed n seq obj ;
+: check-for-compound-syntax ( n/f seq obj -- n/f seq obj )
+    dup length 1 > [ compound-syntax-disallowed ] when ;
+
+: check-compound-loop ( n/f string -- n/f string ? )
+    [ ] [ peek-from ] [ previous-from ] 2tri
+    [ blank? ] bi@ or not ! no blanks between tokens
+    pick and ; ! and a valid index
+
+: lex-factor ( n/f string/f -- n'/f string literal/f )
+    [
+        ! Compound syntax loop
+        [
+            lex-factor-top f like [ , ] when*
+            ! concatenated syntax ( a )[ a 1 + ]( b )
+            check-compound-loop
+        ] loop
+    ] { } make
+    check-for-compound-syntax
+    ! concat ! "ALIAS: n*quot (n*quot)" string>literals ... breaks here
+    ?first f like ;
+
+: string>literals ( string -- sequence )
+    [ 0 ] dip [
+        [ lex-factor [ , ] when* over ] loop
+    ] { } make 2nip ;
+
+: vocab>literals ( vocab -- sequence )
+    ".private" ?tail drop
+    vocab-source-path utf8 file-contents string>literals ;
+
+: path>literals ( path -- sequence )
+    utf8 file-contents string>literals ;
+
+: lex-paths ( vocabs -- assoc )
+    [ [ path>literals ] [ nip ] recover ] map-zip ;
+
+: lex-vocabs ( vocabs -- assoc )
+    [ [ vocab>literals ] [ nip ] recover ] map-zip ;
+
+: failed-lexing ( assoc -- assoc' ) [ nip array? ] assoc-reject ;
+
+: lex-core ( -- assoc ) core-bootstrap-vocabs lex-vocabs ;
+: lex-basis ( -- assoc ) basis-vocabs lex-vocabs ;
+: lex-extra ( -- assoc ) extra-vocabs lex-vocabs ;
+: lex-roots ( -- assoc ) lex-core lex-basis lex-extra 3append ;
+
+: lex-docs ( -- assoc ) all-docs-paths lex-paths ;
+: lex-tests ( -- assoc ) all-tests-paths lex-paths ;
+
+: lex-all ( -- assoc )
+    lex-roots lex-docs lex-tests 3append ;
diff --git a/extra/modern/out/authors.txt b/extra/modern/out/authors.txt
new file mode 100644
index 0000000000..7c1b2f2279
--- /dev/null
+++ b/extra/modern/out/authors.txt
@@ -0,0 +1 @@
+Doug Coleman
diff --git a/extra/modern/out/out.factor b/extra/modern/out/out.factor
new file mode 100644
index 0000000000..86a8cf81d9
--- /dev/null
+++ b/extra/modern/out/out.factor
@@ -0,0 +1,108 @@
+! Copyright (C) 2017 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors arrays assocs combinators.short-circuit
+constructors continuations io io.encodings.utf8 io.files
+io.streams.string kernel modern modern.paths modern.slices
+prettyprint sequences sequences.extras splitting strings
+vocabs.loader ;
+IN: modern.out
+
+: token? ( obj -- ? )
+    { [ slice? ] [ seq>> string? ] } 1&& ;
+
+TUPLE: renamed slice string ;
+CONSTRUCTOR: <renamed> renamed ( slice string -- obj ) ;
+
+: trim-before-newline ( seq -- seq' )
+    dup [ char: \s = not ] find
+    { char: \r char: \n } member?
+    [ tail-slice ] [ drop ] if ;
+
+: write-whitespace ( last obj -- )
+    swap
+    [ swap slice-between ] [ slice-before ] if*
+    trim-before-newline io::write ;
+
+GENERIC: write-literal* ( last obj -- last' )
+M: slice write-literal* [ write-whitespace ] [ write ] [ ] tri ;
+M: array write-literal* [ write-literal* ] each ;
+M: renamed write-literal* [ slice>> write-whitespace ] [ string>> write ] [ slice>> ] tri ; ! for refactoring
+
+
+
+DEFER: map-literals
+: (map-literals) ( obj quot: ( obj -- obj' ) -- seq )
+    over [ array? ] any? [
+        [ call drop ] [ map-literals ] 2bi
+    ] [
+        over array? [ map-literals ] [ call ] if
+    ] if ; inline recursive
+
+: map-literals ( obj quot: ( obj -- obj' ) -- seq )
+    '[ _ (map-literals) ] map ; inline recursive
+
+
+
+! Start with no slice as ``last``
+: write-literal ( obj -- ) f swap write-literal* drop ;
+
+: write-modern-string ( seq -- string )
+    [ write-literal ] with-string-writer ; inline
+
+: write-modern-path ( seq path -- )
+    utf8 [ write-literal nl ] with-file-writer ; inline
+
+: write-modern-vocab ( seq vocab -- )
+    vocab-source-path write-modern-path ; inline
+
+: rewrite-path ( path quot: ( obj -- obj' ) -- )
+    ! dup print
+    '[ [ path>literals _ map-literals ] [ ] bi write-modern-path ]
+    [ drop . ] recover ; inline recursive
+
+: rewrite-string ( string quot: ( obj -- obj' ) -- )
+    ! dup print
+    [ string>literals ] dip map-literals write-modern-string ; inline recursive
+
+: rewrite-paths ( seq quot: ( obj -- obj' ) -- ) '[ _ rewrite-path ] each ; inline recursive
+
+: rewrite-vocab ( vocab quot: ( obj -- obj' ) -- )
+    [ [ vocab>literals ] dip map-literals ] 2keep drop write-modern-vocab ; inline recursive
+
+: rewrite-string-exact ( string -- string' )
+    string>literals write-modern-string ;
+
+![[
+: rewrite-path-exact ( path -- )
+    [ path>literals ] [ ] bi write-modern-path ;
+
+: rewrite-vocab-exact ( name -- )
+    vocab-source-path rewrite-path-exact ;
+
+: rewrite-paths ( paths -- )
+    [ rewrite-path-exact ] each ;
+]]
+
+: strings-core-to-file ( -- )
+    core-bootstrap-vocabs
+    [ ".private" ?tail drop vocab-source-path utf8 file-contents ] map-zip
+    [ "[========[" dup matching-delimiter-string surround ] assoc-map
+    [
+        first2 [ "VOCAB: " prepend ] dip " " glue
+    ] map
+    [ "    " prepend ] map "\n\n" join
+    "<VOCAB-ROOT: factorcode-core \"https://factorcode.org/git/factor.git\" \"core/\"\n"
+    "\n;VOCAB-ROOT>" surround "resource:core-strings.factor" utf8 set-file-contents ;
+
+: parsed-core-to-file ( -- )
+    core-bootstrap-vocabs
+    [ vocab>literals ] map-zip
+    [
+        first2 [ "<VOCAB: " prepend ] dip
+        >strings
+        ! [ 3 head ] [ 3 tail* ] bi [ >strings ] bi@ { "..." } glue
+        ";VOCAB>" 3array
+    ] map 1array
+
+    { "<VOCAB-ROOT:" "factorcode-core" "https://factorcode.org/git/factor.git" "core/" }
+    { ";VOCAB-ROOT>" } surround "resource:core-parsed.factor" utf8 [ ... ] with-file-writer ;
diff --git a/extra/modern/paths/authors.txt b/extra/modern/paths/authors.txt
new file mode 100644
index 0000000000..7c1b2f2279
--- /dev/null
+++ b/extra/modern/paths/authors.txt
@@ -0,0 +1 @@
+Doug Coleman
diff --git a/extra/modern/paths/paths.factor b/extra/modern/paths/paths.factor
new file mode 100644
index 0000000000..d8f896e471
--- /dev/null
+++ b/extra/modern/paths/paths.factor
@@ -0,0 +1,107 @@
+! Copyright (C) 2015 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors combinators.smart io.files kernel sequences
+splitting vocabs.files vocabs.hierarchy vocabs.loader
+vocabs.metadata sets ;
+IN: modern.paths
+
+ERROR: not-a-source-path path ;
+
+: vocabs-from ( root -- vocabs )
+    "" disk-vocabs-in-root/prefix
+    no-prefixes [ name>> ] map ;
+
+: core-vocabs ( -- seq ) "resource:core" vocabs-from ;
+: less-core-test-vocabs ( seq -- seq' )
+    {
+        "vocabs.loader.test.a"
+        "vocabs.loader.test.b"
+        "vocabs.loader.test.c"
+        "vocabs.loader.test.d"
+        "vocabs.loader.test.e"
+        "vocabs.loader.test.f"
+        "vocabs.loader.test.g"
+        "vocabs.loader.test.h"
+        "vocabs.loader.test.i"
+        "vocabs.loader.test.j"
+        "vocabs.loader.test.k"
+        "vocabs.loader.test.l"
+        "vocabs.loader.test.m"
+        "vocabs.loader.test.n"
+        "vocabs.loader.test.o"
+        "vocabs.loader.test.p"
+    } diff ;
+
+: core-bootstrap-vocabs ( -- seq )
+    core-vocabs less-core-test-vocabs ;
+
+: basis-vocabs ( -- seq ) "resource:basis" vocabs-from ;
+: extra-vocabs ( -- seq ) "resource:extra" vocabs-from ;
+: all-vocabs ( -- seq )
+    [
+        core-vocabs
+        basis-vocabs
+        extra-vocabs
+    ] { } append-outputs-as ;
+
+: filter-exists ( seq -- seq' ) [ exists? ] filter ;
+
+! These paths have syntax errors on purpose...
+: reject-some-paths ( seq -- seq' )
+    {
+        "resource:core/vocabs/loader/test/a/a.factor"
+        "resource:core/vocabs/loader/test/b/b.factor"
+        "resource:core/vocabs/loader/test/c/c.factor"
+        ! Here down have parse errors
+        "resource:core/vocabs/loader/test/d/d.factor"
+        "resource:core/vocabs/loader/test/e/e.factor"
+        "resource:core/vocabs/loader/test/f/f.factor"
+        "resource:core/vocabs/loader/test/g/g.factor"
+        "resource:core/vocabs/loader/test/h/h.factor"
+        "resource:core/vocabs/loader/test/i/i.factor"
+        "resource:core/vocabs/loader/test/j/j.factor"
+        "resource:core/vocabs/loader/test/k/k.factor"
+        "resource:core/vocabs/loader/test/l/l.factor"
+        "resource:core/vocabs/loader/test/m/m.factor"
+        "resource:core/vocabs/loader/test/n/n.factor"
+        "resource:core/vocabs/loader/test/o/o.factor"
+        "resource:core/vocabs/loader/test/p/p.factor"
+    } diff
+    ! Don't parse .modern files yet
+    [ ".modern" tail? ] reject ;
+
+: modern-source-paths ( names -- paths )
+    [ vocab-source-path ] map filter-exists reject-some-paths ;
+: modern-docs-paths ( names -- paths )
+    [ vocab-docs-path ] map filter-exists reject-some-paths ;
+: modern-tests-paths ( names -- paths )
+    [ vocab-tests ] map concat filter-exists reject-some-paths ;
+
+: all-source-paths ( -- seq )
+    all-vocabs modern-source-paths ;
+
+: core-docs-paths ( -- seq ) core-vocabs modern-docs-paths ;
+: basis-docs-paths ( -- seq ) basis-vocabs modern-docs-paths ;
+: extra-docs-paths ( -- seq ) extra-vocabs modern-docs-paths ;
+
+: core-test-paths ( -- seq ) core-vocabs modern-tests-paths ;
+: basis-test-paths ( -- seq ) basis-vocabs modern-tests-paths ;
+: extra-test-paths ( -- seq ) extra-vocabs modern-tests-paths ;
+
+
+: all-docs-paths ( -- seq ) all-vocabs modern-docs-paths ;
+ : all-tests-paths ( -- seq ) all-vocabs modern-tests-paths ;
+
+: all-paths ( -- seq )
+    [
+        all-source-paths all-docs-paths all-tests-paths
+    ] { } append-outputs-as ;
+
+: core-source-paths ( -- seq )
+    core-vocabs modern-source-paths reject-some-paths ;
+: basis-source-paths ( -- seq )
+    basis-vocabs
+    modern-source-paths reject-some-paths ;
+: extra-source-paths ( -- seq )
+    extra-vocabs
+    modern-source-paths reject-some-paths ;
diff --git a/extra/modern/slices/slices.factor b/extra/modern/slices/slices.factor
new file mode 100644
index 0000000000..ad14276a06
--- /dev/null
+++ b/extra/modern/slices/slices.factor
@@ -0,0 +1,228 @@
+! Copyright (C) 2016 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors assocs fry kernel locals math sequences
+sequences.deep sequences.extras strings unicode ;
+IN: modern.slices
+
+: >strings ( seq -- str )
+    [ dup slice? [ >string ] when ] deep-map ;
+
+: matching-delimiter ( ch -- ch' )
+    H{
+        { CHAR: ( CHAR: ) }
+        { CHAR: [ CHAR: ] }
+        { CHAR: { CHAR: } }
+        { CHAR: < CHAR: > }
+        { CHAR: : CHAR: ; }
+    } ?at drop ;
+
+: matching-delimiter-string ( string -- string' )
+    [ matching-delimiter ] map ;
+
+: matching-section-delimiter ( string -- string' )
+    dup ":" tail? [
+        rest but-last ";" ">" surround
+    ] [
+        rest ">" append
+    ] if ;
+
+ERROR: unexpected-end n string ;
+: nth-check-eof ( n string -- nth )
+    2dup ?nth [ 2nip ] [ unexpected-end ] if* ;
+
+: peek-from ( n/f string -- ch )
+    over [ ?nth ] [ 2drop f ] if ;
+
+: previous-from ( n/f string -- ch )
+    over [ [ 1 - ] dip ?nth ] [ 2drop f ] if ;
+
+! Allow eof
+: next-char-from ( n/f string -- n'/f string ch/f )
+    over [
+        2dup ?nth [ [ 1 + ] 2dip ] [ f ] if*
+    ] [
+        [ 2drop f ] [ nip ] 2bi f
+    ] if ;
+
+: prev-char-from-slice-end ( slice -- ch/f )
+    [ to>> 2 - ] [ seq>> ] bi ?nth ;
+
+: prev-char-from-slice ( slice -- ch/f )
+    [ from>> 1 - ] [ seq>> ] bi ?nth ;
+
+: next-char-from-slice ( slice -- ch/f )
+    [ to>> ] [ seq>> ] bi ?nth ;
+
+: char-before-slice ( slice -- ch/f )
+    [ from>> 1 - ] [ seq>> ] bi ?nth ;
+
+: char-after-slice ( slice -- ch/f )
+    [ to>> ] [ seq>> ] bi ?nth ;
+
+: find-from* ( ... n seq quot: ( ... elt -- ... ? ) -- ... i elt ? )
+    [ find-from ] 2keep drop
+    pick [ drop t ] [ length -rot nip f ] if ; inline
+
+: skip-blank-from ( n string -- n' string )
+    over [
+        [ [ blank? not ] find-from* 2drop ] keep
+    ] when ; inline
+
+: skip-til-eol-from ( n string -- n' string )
+    [ [ "\r\n" member? ] find-from* 2drop ] keep ; inline
+
+! Don't include the whitespace in the slice
+:: slice-til-whitespace ( n string -- n' string slice/f ch/f )
+    n [
+        n string [ "\s\r\n" member? ] find-from :> ( n' ch )
+        n' string
+        n n' string ?<slice>
+        ch
+    ] [
+        f string f f
+    ] if ; inline
+
+:: (slice-until) ( n string quot -- n' string slice/f ch/f )
+    n string quot find-from :> ( n' ch )
+    n' string
+    n n' string ?<slice>
+    ch ; inline
+
+: slice-until ( n string quot -- n' string slice/f )
+    (slice-until) drop ; inline
+
+:: slice-til-not-whitespace ( n string -- n' string slice/f ch/f )
+    n [
+        n string [ "\s\r\n" member? not ] find-from :> ( n' ch )
+        n' string
+        n n' string ?<slice>
+        ch
+    ] [
+        n string f f
+    ] if ; inline
+
+: skip-whitespace ( n/f string -- n'/f string )
+    slice-til-not-whitespace 2drop ;
+
+: empty-slice-end ( seq -- slice )
+    [ length dup ] [ ] bi <slice> ; inline
+
+: empty-slice-from ( n seq -- slice )
+    dupd <slice> ; inline
+
+:: slice-til-eol ( n string -- n' string slice/f ch/f )
+    n [
+        n string '[ "\r\n" member? ] find-from :> ( n' ch )
+        n' string
+        n n' string ?<slice>
+        ch
+    ] [
+        n string string empty-slice-end f
+    ] if ; inline
+
+:: merge-slice-til-eol-slash'' ( n string -- n' string slice/f ch/f )
+    n [
+        n string '[ "\r\n\\" member? ] find-from :> ( n' ch )
+        n' string
+        n n' string ?<slice>
+        ch
+    ] [
+        n string string empty-slice-end f
+    ] if ; inline
+
+: merge-slice-til-whitespace ( n string slice --  n' string slice' )
+    pick [
+        [ slice-til-whitespace drop ] dip merge-slices
+    ] when ;
+
+: merge-slice-til-eol ( n string slice --  n' string slice' )
+    [ slice-til-eol drop ] dip merge-slices ;
+
+: slice-between ( slice1 slice2 -- slice )
+    ! ensure-same-underlying
+    slice-order-by-from
+    [ to>> ]
+    [ [ from>> 2dup < [ swap ] unless ] [ seq>> ] bi ] bi* <slice> ;
+
+: slice-before ( slice -- slice' )
+    [ drop 0 ] [ from>> ] [ seq>> ] tri <slice> ;
+
+: (?nth) ( n/f string/f -- obj/f )
+    over [ (?nth) ] [ 2drop f ] if ;
+
+:: merge-slice-til-eol-slash' ( n string slice -- n' string slice/f ch/f )
+    n string merge-slice-til-eol-slash'' :> ( n' string' slice' ch' )
+    ch' CHAR: \\ = [
+        n' 1 + string' (?nth) "\r\n" member? [
+            n' 2 + string' slice slice' span-slices merge-slice-til-eol-slash'
+        ] [
+            "omg" throw
+        ] if
+    ] [
+        n' string' slice slice' span-slices ch'
+    ] if ;
+
+! Supports \ at eol (with no space after it)
+: slice-til-eol-slash ( n string -- n' string slice/f ch/f )
+    2dup empty-slice-from merge-slice-til-eol-slash' ;
+
+:: slice-til-separator-inclusive ( n string tokens -- n' string slice/f ch/f )
+    n string '[ tokens member? ] find-from [ dup [ 1 + ] when ] dip  :> ( n' ch )
+    n' string
+    n n' string ?<slice>
+    ch ; inline
+
+: slice-til-separator-exclusive ( n string tokens -- n' string slice/f ch/f )
+    slice-til-separator-inclusive dup [
+        [ [ 1 - ] change-to ] dip
+    ] when ;
+
+! Takes at least one character if not whitespace
+:: slice-til-either ( n string tokens -- n'/f string slice/f ch/f )
+    n [
+        n string '[ tokens member? ] find-from
+        dup "\s\r\n" member? [
+            :> ( n' ch )
+            n' string
+            n n' string ?<slice>
+            ch
+        ] [
+            [ dup [ 1 + ] when ] dip :> ( n' ch )
+            n' string
+            n n' string ?<slice>
+            ch
+        ] if
+    ] [
+        f string f f
+    ] if ; inline
+
+ERROR: subseq-expected-but-got-eof n string expected ;
+
+:: slice-til-string ( n string search --  n' string payload end-string )
+    search string n subseq-start-from :> n'
+    n' [ n string search subseq-expected-but-got-eof ] unless
+    n' search length +  string
+    n n' string ?<slice>
+    n' dup search length + string ?<slice> ;
+
+: modify-from ( slice n -- slice' )
+    '[ from>> _ + ] [ to>> ] [ seq>> ] tri <slice> ;
+
+: modify-to ( slice n -- slice' )
+    [ [ from>> ] [ to>> ] [ seq>> ] tri ] dip
+    swap [ + ] dip <slice> ;
+
+! { CHAR: \] [ read-closing ] }
+! { CHAR: \} [ read-closing ] }
+! { CHAR: \) [ read-closing ] }
+: read-closing ( n string tok -- n string tok )
+    dup length 1 = [
+        -1 modify-to [ 1 - ] 2dip
+    ] unless ;
+
+: rewind-slice ( n string slice -- n' string )
+    pick [
+        length swap [ - ] dip
+    ] [
+        [ nip ] dip [ [ length ] bi@ - ] 2keep drop
+    ] if ; inline