diff --git a/basis/images/normalization/normalization.factor b/basis/images/normalization/normalization.factor
index 6eaca01e15..db68e4bad6 100644
--- a/basis/images/normalization/normalization.factor
+++ b/basis/images/normalization/normalization.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors alien.c-types byte-arrays combinators fry
 grouping images kernel locals math math.vectors
-sequences specialized-arrays half-floats ;
+sequences specialized-arrays math.floats.half ;
 FROM: alien.c-types => float ;
 SPECIALIZED-ARRAY: half
 SPECIALIZED-ARRAY: float
diff --git a/basis/half-floats/authors.txt b/basis/math/floats/half/authors.txt
similarity index 100%
rename from basis/half-floats/authors.txt
rename to basis/math/floats/half/authors.txt
diff --git a/basis/half-floats/half-floats-tests.factor b/basis/math/floats/half/half-tests.factor
similarity index 93%
rename from basis/half-floats/half-floats-tests.factor
rename to basis/math/floats/half/half-tests.factor
index d6b26cb129..82db3d195b 100644
--- a/basis/half-floats/half-floats-tests.factor
+++ b/basis/math/floats/half/half-tests.factor
@@ -1,7 +1,7 @@
-USING: accessors alien.c-types alien.syntax half-floats kernel
+USING: accessors alien.c-types alien.syntax math.floats.half kernel
 math tools.test specialized-arrays alien.data classes.struct ;
 SPECIALIZED-ARRAY: half
-IN: half-floats.tests
+IN: math.floats.half.tests
 
 [ HEX: 0000 ] [  0.0  half>bits ] unit-test
 [ HEX: 8000 ] [ -0.0  half>bits ] unit-test
diff --git a/basis/half-floats/half-floats.factor b/basis/math/floats/half/half.factor
similarity index 98%
rename from basis/half-floats/half-floats.factor
rename to basis/math/floats/half/half.factor
index 4c84bb81cc..ffa3550452 100644
--- a/basis/half-floats/half-floats.factor
+++ b/basis/math/floats/half/half.factor
@@ -2,7 +2,7 @@
 USING: accessors alien.accessors alien.c-types alien.data
 alien.syntax kernel math math.order ;
 FROM: math => float ;
-IN: half-floats
+IN: math.floats.half
 
 : half>bits ( float -- bits )
     float>bits
diff --git a/basis/half-floats/summary.txt b/basis/math/floats/half/summary.txt
similarity index 100%
rename from basis/half-floats/summary.txt
rename to basis/math/floats/half/summary.txt
diff --git a/build-support/factor.sh b/build-support/factor.sh
index d8b547d8d6..9da4ae295a 100755
--- a/build-support/factor.sh
+++ b/build-support/factor.sh
@@ -195,8 +195,9 @@ find_architecture() {
 }
 
 write_test_program() {
-    $ECHO "#include <stdio.h>" > $C_WORD.c
-    $ECHO "int main(){printf(\"%ld\", (long)(8*sizeof(void*))); return 0; }" >> $C_WORD.c
+    #! Must be 'echo'
+    echo "#include <stdio.h>" > $C_WORD.c
+    echo "int main(){printf(\"%ld\", (long)(8*sizeof(void*))); return 0; }" >> $C_WORD.c
 }
 
 c_find_word_size() {
diff --git a/extra/game/models/half-edge/authors.txt b/extra/game/models/half-edge/authors.txt
new file mode 100644
index 0000000000..f13c9c1e77
--- /dev/null
+++ b/extra/game/models/half-edge/authors.txt
@@ -0,0 +1 @@
+Joe Groff
diff --git a/extra/game/models/half-edge/half-edge-tests.factor b/extra/game/models/half-edge/half-edge-tests.factor
new file mode 100644
index 0000000000..cbfe514d7e
--- /dev/null
+++ b/extra/game/models/half-edge/half-edge-tests.factor
@@ -0,0 +1,69 @@
+USING: accessors game.models.half-edge kernel sequences
+tools.test ;
+IN: game.models.half-edge.tests
+
+CONSTANT: cube-edges
+    {
+        T{ edge { face 0 } { vertex  0 } { opposite-edge  6 } { next-edge  1 } }
+        T{ edge { face 0 } { vertex  1 } { opposite-edge 19 } { next-edge  2 } }
+        T{ edge { face 0 } { vertex  3 } { opposite-edge 12 } { next-edge  3 } }
+        T{ edge { face 0 } { vertex  2 } { opposite-edge 21 } { next-edge  0 } }
+
+        T{ edge { face 1 } { vertex  4 } { opposite-edge 10 } { next-edge  5 } }
+        T{ edge { face 1 } { vertex  5 } { opposite-edge 16 } { next-edge  6 } }
+        T{ edge { face 1 } { vertex  1 } { opposite-edge  0 } { next-edge  7 } }
+        T{ edge { face 1 } { vertex  0 } { opposite-edge 20 } { next-edge  4 } }
+
+        T{ edge { face 2 } { vertex  6 } { opposite-edge 14 } { next-edge  9 } }
+        T{ edge { face 2 } { vertex  7 } { opposite-edge 17 } { next-edge 10 } }
+        T{ edge { face 2 } { vertex  5 } { opposite-edge  4 } { next-edge 11 } }
+        T{ edge { face 2 } { vertex  4 } { opposite-edge 23 } { next-edge  8 } }
+
+        T{ edge { face 3 } { vertex  2 } { opposite-edge  2 } { next-edge 13 } }
+        T{ edge { face 3 } { vertex  3 } { opposite-edge 22 } { next-edge 14 } }
+        T{ edge { face 3 } { vertex  7 } { opposite-edge  8 } { next-edge 15 } }
+        T{ edge { face 3 } { vertex  6 } { opposite-edge 18 } { next-edge 12 } }
+
+        T{ edge { face 4 } { vertex  1 } { opposite-edge  5 } { next-edge 17 } }
+        T{ edge { face 4 } { vertex  5 } { opposite-edge  9 } { next-edge 18 } }
+        T{ edge { face 4 } { vertex  7 } { opposite-edge 13 } { next-edge 19 } }
+        T{ edge { face 4 } { vertex  3 } { opposite-edge  1 } { next-edge 16 } }
+
+        T{ edge { face 5 } { vertex  4 } { opposite-edge  7 } { next-edge 21 } }
+        T{ edge { face 5 } { vertex  0 } { opposite-edge  3 } { next-edge 22 } }
+        T{ edge { face 5 } { vertex  2 } { opposite-edge 15 } { next-edge 23 } }
+        T{ edge { face 5 } { vertex  6 } { opposite-edge 11 } { next-edge 20 } }
+    }
+
+: connect-cube-edges ( -- )
+    cube-edges [
+        [ cube-edges nth ] change-opposite-edge
+        [ cube-edges nth ] change-next-edge
+        drop
+    ] each ;
+
+connect-cube-edges
+
+[ 0 1 ]
+[ cube-edges first edge-vertices ] unit-test
+
+[ { 0 0 0 } ]
+[ cube-edges first vertex-edges [ vertex>> ] map ] unit-test
+
+[ 3 ]
+[ cube-edges first vertex-valence ] unit-test
+
+[ { 0 1 3 2 } ]
+[ cube-edges first face-edges [ vertex>> ] map ] unit-test
+
+[ 4 ]
+[ cube-edges first face-sides ] unit-test
+
+[ { 1 4 2 } ]
+[ cube-edges first vertex-neighbors ] unit-test
+
+[ { 3 5 6 } ]
+[ cube-edges first vertex-diagonals ] unit-test
+
+[ { 1 4 3 5 } ]
+[ cube-edges first face-neighbors ] unit-test
diff --git a/extra/game/models/half-edge/half-edge.factor b/extra/game/models/half-edge/half-edge.factor
new file mode 100644
index 0000000000..eeb3e6116f
--- /dev/null
+++ b/extra/game/models/half-edge/half-edge.factor
@@ -0,0 +1,54 @@
+! (c)2010 Joe Groff bsd license
+USING: accessors arrays fry kernel locals math sequences ;
+IN: game.models.half-edge
+
+TUPLE: edge < identity-tuple face vertex opposite-edge next-edge ;
+
+: edge-vertices ( edge -- start end )
+    [ vertex>> ] [ opposite-edge>> vertex>> ] bi ;
+
+! building blocks for edge loop iteration
+
+: (collect) ( in quot iterator -- out )
+    [ collector ] dip dip >array ; inline
+
+: (reduce) ( in initial quot iterator -- accum )
+    [ swap ] 2dip call ; inline
+
+: (count) ( in iterator -- count )
+    [ 0 [ drop 1 + ] ] dip (reduce) ; inline
+
+: edge-loop ( ..a edge quot: ( ..a edge -- ..b ) next-edge-quot: ( ..b edge -- ..a edge' ) -- ..a )
+    pick '[ _ _ bi dup _ eq? not ] loop drop ; inline
+
+! iterate over related edges
+
+: each-vertex-edge ( ... edge quot: ( ... edge -- ... ) -- ... )
+    [ opposite-edge>> next-edge>> ] edge-loop ; inline
+
+: each-face-edge ( ... edge quot: ( ... edge -- ... ) -- ... )
+    [ next-edge>> ] edge-loop ; inline
+
+! 
+
+: vertex-edges ( edge -- edges )
+    [ ] [ each-vertex-edge ] (collect) ;
+
+: vertex-neighbors ( edge -- edges )
+    [ opposite-edge>> vertex>> ] [ each-vertex-edge ] (collect) ;
+
+: vertex-diagonals ( edge -- edges )
+    [ next-edge>> opposite-edge>> vertex>> ] [ each-vertex-edge ] (collect) ;
+
+: vertex-valence ( edge -- count )
+    [ each-vertex-edge ] (count) ;
+
+: face-edges ( edge -- edges )
+    [ ] [ each-face-edge ] (collect) ;
+
+: face-neighbors ( edge -- edges )
+    [ opposite-edge>> face>> ] [ each-face-edge ] (collect) ;
+
+: face-sides ( edge -- count )
+    [ each-face-edge ] (count) ;
+
diff --git a/extra/game/models/half-edge/summary.txt b/extra/game/models/half-edge/summary.txt
new file mode 100644
index 0000000000..6f0aac5c4a
--- /dev/null
+++ b/extra/game/models/half-edge/summary.txt
@@ -0,0 +1 @@
+Iterators for half-edge geometry structures
diff --git a/extra/gpu/render/render.factor b/extra/gpu/render/render.factor
index 6e66832a2f..d1cb0357ed 100755
--- a/extra/gpu/render/render.factor
+++ b/extra/gpu/render/render.factor
@@ -4,7 +4,7 @@ assocs classes classes.mixin classes.parser classes.singleton classes.struct
 classes.tuple classes.tuple.private combinators combinators.tuple destructors fry
 generic generic.parser gpu gpu.buffers gpu.framebuffers
 gpu.framebuffers.private gpu.shaders gpu.shaders.private gpu.state
-gpu.textures gpu.textures.private half-floats images kernel
+gpu.textures gpu.textures.private math.floats.half images kernel
 lexer locals math math.order math.parser namespaces opengl
 opengl.gl parser quotations sequences slots sorting
 specialized-arrays strings ui.gadgets.worlds variants
diff --git a/extra/gpu/shaders/shaders.factor b/extra/gpu/shaders/shaders.factor
index 8a2931e431..d1c137128a 100755
--- a/extra/gpu/shaders/shaders.factor
+++ b/extra/gpu/shaders/shaders.factor
@@ -8,7 +8,7 @@ kernel lexer literals locals math math.parser memoize multiline namespaces
 opengl opengl.gl opengl.shaders parser quotations sequences
 specialized-arrays splitting strings tr ui.gadgets.worlds
 variants vectors vocabs vocabs.loader vocabs.parser words
-words.constant half-floats typed ;
+words.constant math.floats.half typed ;
 QUALIFIED-WITH: alien.c-types c
 SPECIALIZED-ARRAY: int
 SPECIALIZED-ARRAY: void*