diff --git a/extra/sequences/abbrev/abbrev-docs.factor b/extra/sequences/abbrev/abbrev-docs.factor
new file mode 100644
index 0000000000..ae351914de
--- /dev/null
+++ b/extra/sequences/abbrev/abbrev-docs.factor
@@ -0,0 +1,28 @@
+! Copyright (C) 2009 Maximilian Lupke.
+! See http://factorcode.org/license.txt for BSD license.
+USING: assocs help.markup help.syntax sequences ;
+IN: sequences.abbrev
+
+HELP: abbrev
+{ $values
+    { "seqs" sequence }
+    { "assoc" assoc }
+}
+{ $description "Calculates an assoc of { prefix sequence } pairs with prefix being an prefix of each element of sequence for each element in " { $snippet "seqs" } "." } ;
+
+HELP: unique-abbrev
+{ $values
+    { "seqs" sequence }
+    { "assoc" assoc }
+}
+{ $description "Calculates an assoc of { prefix { sequence } } pairs with prefix being an unambiguous prefix of sequence in seqs." } ;
+
+ARTICLE: "sequences.abbrev" "Examples of abbrev usage"
+"It is probably easiest to just run examples to understand abbrev."
+{ $code
+    "{ \"hello\" \"help\" } abbrev"
+    "{ \"hello\" \"help\" } unique-abbrev"
+}
+;
+
+ABOUT: "sequences.abbrev"
diff --git a/extra/sequences/abbrev/abbrev-tests.factor b/extra/sequences/abbrev/abbrev-tests.factor
new file mode 100644
index 0000000000..39e445b495
--- /dev/null
+++ b/extra/sequences/abbrev/abbrev-tests.factor
@@ -0,0 +1,26 @@
+USING: assocs sequences.abbrev tools.test ;
+IN: sequences.abbrev.tests
+
+[ { "hello" "help" } ] [
+    "he" { "apple" "hello" "help" } abbrev at
+] unit-test
+
+[ f ] [
+    "he" { "apple" "hello" "help" } unique-abbrev at
+] unit-test
+
+[ { "apple" } ] [
+    "a" { "apple" "hello" "help" } abbrev at
+] unit-test
+
+[ { "apple" } ] [
+    "a" { "apple" "hello" "help" } unique-abbrev at
+] unit-test
+
+[ f ] [
+    "a" { "hello" "help" } abbrev at
+] unit-test
+
+[ f ] [
+    "a" { "hello" "help" } unique-abbrev at
+] unit-test
diff --git a/extra/sequences/abbrev/abbrev.factor b/extra/sequences/abbrev/abbrev.factor
new file mode 100644
index 0000000000..6770a48a3a
--- /dev/null
+++ b/extra/sequences/abbrev/abbrev.factor
@@ -0,0 +1,23 @@
+! Copyright (C) 2009 Maximilian Lupke.
+! See http://factorcode.org/license.txt for BSD license.
+USING: arrays assocs fry kernel math.ranges sequences ;
+IN: sequences.abbrev
+
+<PRIVATE
+
+: prefixes ( seq -- prefixes )
+    dup length [1,b] [ head ] with map ;
+
+: (abbrev) ( seq -- assoc )
+    [ prefixes ] keep 1array '[ _ ] H{ } map>assoc ;
+
+: assoc-merge ( assoc1 assoc2 -- assoc3 )
+    tuck '[ over _ at dup [ append ] [ drop ] if ] assoc-map assoc-union ;
+
+PRIVATE>
+
+: abbrev ( seqs -- assoc )
+    [ (abbrev) ] map H{ } [ assoc-merge ] reduce ;
+
+: unique-abbrev ( seqs -- assoc )
+    abbrev [ nip length 1 = ] assoc-filter ;
diff --git a/extra/sequences/abbrev/authors.txt b/extra/sequences/abbrev/authors.txt
new file mode 100644
index 0000000000..758ea89529
--- /dev/null
+++ b/extra/sequences/abbrev/authors.txt
@@ -0,0 +1 @@
+Maximilian Lupke