diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 15c523d6..324576db 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1102,6 +1102,7 @@ Mercury:
   lexer: Prolog
   extensions:
   - .m
+  - .moo
 
 MiniD: # Legacy
   searchable: false
diff --git a/lib/linguist/samples.json b/lib/linguist/samples.json
index 652fef38..073330af 100644
--- a/lib/linguist/samples.json
+++ b/lib/linguist/samples.json
@@ -217,6 +217,9 @@
     "ABAP": [
       ".abap"
     ],
+    "Moocode": [
+      ".moo"
+    ],
     "Java": [
       ".java"
     ],
@@ -340,7 +343,8 @@
       ".bsv"
     ],
     "Mercury": [
-      ".m"
+      ".m",
+      ".moo"
     ],
     "Erlang": [
       ".erl",
@@ -563,8 +567,8 @@
       "zshrc"
     ]
   },
-  "tokens_total": 484777,
-  "languages_total": 561,
+  "tokens_total": 485338,
+  "languages_total": 564,
   "tokens": {
     "Groovy": {
       "SHEBANG#!groovy": 1,
@@ -24491,6 +24495,41 @@
       "pos": 2,
       "endclass.": 1
     },
+    "Moocode": {
+      "@verb": 1,
+      "toy": 3,
+      "do_the_work": 3,
+      "this": 5,
+      "none": 1,
+      "@program": 2,
+      "if": 4,
+      "(": 13,
+      "this.wound": 8,
+      ")": 13,
+      "object_utils": 1,
+      "isa": 1,
+      "this.location": 3,
+      "room": 1,
+      "announce_all": 2,
+      "this.name": 4,
+      "continue_msg": 1,
+      ";": 8,
+      "-": 1,
+      "fork": 1,
+      "endfork": 1,
+      "else": 1,
+      "wind_down_msg": 1,
+      "endif": 4,
+      "<": 1,
+      ".": 2,
+      "wind": 1,
+      "+": 1,
+      "player": 1,
+      "tell": 1,
+      "player.location": 1,
+      "announce": 1,
+      "player.name": 1
+    },
     "Java": {
       "package": 6,
       "clojure.lang": 1,
@@ -36959,29 +36998,29 @@
     },
     "Mercury": {
       "%": 416,
-      "-": 6914,
-      "module": 45,
+      "-": 6967,
+      "module": 46,
       "rot13_verbose.": 1,
-      "interface.": 12,
-      "import_module": 124,
+      "interface.": 13,
+      "import_module": 126,
       "io.": 8,
-      "pred": 253,
+      "pred": 255,
       "main": 15,
-      "(": 3284,
+      "(": 3351,
       "io__state": 4,
-      ")": 3284,
-      ".": 592,
-      "mode": 6,
+      ")": 3351,
+      ".": 610,
+      "mode": 8,
       "di": 54,
       "uo": 58,
-      "is": 244,
-      "det.": 182,
-      "implementation.": 11,
-      "char": 7,
-      "int": 124,
-      "require.": 5,
+      "is": 246,
+      "det.": 184,
+      "implementation.": 12,
+      "char": 10,
+      "int": 129,
+      "require.": 6,
       "rot13a/2": 1,
-      "A": 6,
+      "A": 14,
       "table": 1,
       "to": 16,
       "map": 7,
@@ -36996,8 +37035,8 @@
       "input": 1,
       "not": 7,
       "rot13a": 55,
-      "in": 506,
-      "out": 334,
+      "in": 510,
+      "out": 337,
       "semidet.": 10,
       "rot13/2": 1,
       "Applies": 1,
@@ -37011,13 +37050,13 @@
       "else": 8,
       "io__read_char": 1,
       "Res": 8,
-      "{": 23,
+      "{": 27,
       "ok": 3,
-      "}": 24,
+      "}": 28,
       "io__write_char": 1,
-      ";": 898,
-      "eof": 3,
-      "error": 6,
+      ";": 913,
+      "eof": 6,
+      "error": 7,
       "ErrorCode": 4,
       "io__error_message": 2,
       "ErrorMessage": 4,
@@ -37041,10 +37080,10 @@
       "sub_string_search": 1,
       "Index": 3,
       "NewIndex": 2,
-      "+": 125,
+      "+": 127,
       "mod": 1,
-      "*": 18,
-      "//": 1,
+      "*": 20,
+      "//": 2,
       "index_det": 1,
       "read_char": 1,
       "print": 3,
@@ -37056,9 +37095,9 @@
       "store": 52,
       "T": 52,
       "where": 8,
-      "[": 184,
-      "]": 184,
-      "type": 56,
+      "[": 203,
+      "]": 203,
+      "type": 57,
       "S": 133,
       "instance": 4,
       "io.state": 3,
@@ -37132,7 +37171,7 @@
       "store_ref": 1,
       "store.new_ref": 1,
       "store.ref_functor": 1,
-      "string": 114,
+      "string": 115,
       "store.arg_ref": 1,
       "ArgT": 4,
       "store.new_arg_ref": 3,
@@ -37203,7 +37242,7 @@
       "representation": 1,
       "pragma": 41,
       "foreign_type": 10,
-      "C": 24,
+      "C": 34,
       "MR_Word": 24,
       "can_pass_as_mercury_type": 5,
       "equality": 5,
@@ -37287,7 +37326,7 @@
       "FieldInfo": 1,
       "Constructors": 2,
       "init": 8,
-      "num": 8,
+      "num": 11,
       "setField": 4,
       "Set": 2,
       "according": 2,
@@ -37409,7 +37448,7 @@
       "mdbcomp.prim_data.": 3,
       "parse_tree.": 1,
       "parse_tree.prog_data.": 2,
-      "list.": 3,
+      "list.": 4,
       "maybe.": 3,
       "term.": 3,
       "polymorphism_process_module": 2,
@@ -37425,7 +37464,7 @@
       "pred_info": 20,
       "proc_info": 11,
       "proc_id": 12,
-      "list": 77,
+      "list": 82,
       "prog_var": 58,
       "builtin_state": 1,
       "maybe": 20,
@@ -37547,7 +37586,7 @@
       "ArgTypes": 6,
       "pred_info_set_arg_types": 1,
       "PredInfo1": 5,
-      "|": 28,
+      "|": 38,
       "OldHeadVarTypes": 2,
       "type_list_subsumes": 2,
       "Subn": 3,
@@ -38292,6 +38331,32 @@
       "NonLocals1": 2,
       "CallGoalExpr": 2,
       "CallGoal": 2,
+      "expr.": 1,
+      "token": 5,
+      "parse": 1,
+      "exprn/1": 1,
+      "xx": 1,
+      "scan": 16,
+      "rule": 3,
+      "exprn": 7,
+      "Num": 18,
+      "term": 10,
+      "B": 8,
+      "factor": 6,
+      "/": 1,
+      "Chars": 2,
+      "Toks": 13,
+      "Toks0": 11,
+      "list__reverse": 1,
+      "Cs": 9,
+      "char__is_whitespace": 1,
+      "char__is_digit": 2,
+      "takewhile": 1,
+      "Digits": 2,
+      "Rest": 2,
+      "string__from_char_list": 1,
+      "NumStr": 2,
+      "string__det_to_int": 1,
       "char.": 1,
       "getopt_io.": 1,
       "short_option": 36,
@@ -38378,7 +38443,6 @@
       "debug_code_gen_pred_id": 3,
       "debug_opt": 3,
       "debug_term": 4,
-      "term": 1,
       "termination": 3,
       "analysis": 1,
       "debug_opt_pred_id": 3,
@@ -51924,6 +51988,7 @@
     "Org": 358,
     "Turing": 44,
     "ABAP": 1500,
+    "Moocode": 93,
     "Java": 8987,
     "Omgrofl": 57,
     "GAS": 133,
@@ -51960,7 +52025,7 @@
     "RMarkdown": 19,
     "Stylus": 76,
     "Bluespec": 1298,
-    "Mercury": 30628,
+    "Mercury": 31096,
     "Erlang": 2928,
     "NSIS": 725,
     "Arduino": 20,
@@ -52072,6 +52137,7 @@
     "Org": 1,
     "Turing": 1,
     "ABAP": 1,
+    "Moocode": 2,
     "Java": 6,
     "Omgrofl": 1,
     "GAS": 1,
@@ -52108,7 +52174,7 @@
     "RMarkdown": 1,
     "Stylus": 1,
     "Bluespec": 2,
-    "Mercury": 8,
+    "Mercury": 9,
     "Erlang": 5,
     "NSIS": 2,
     "Arduino": 1,
@@ -52155,5 +52221,5 @@
     "Protocol Buffer": 1,
     "Scheme": 2
   },
-  "md5": "1c540f92a03ec13cf822b38473b5a4ff"
+  "md5": "9dbc6271b8d729f78fea54760082d89a"
 }
\ No newline at end of file
diff --git a/samples/Mercury/expr.moo b/samples/Mercury/expr.moo
new file mode 100644
index 00000000..30a140ab
--- /dev/null
+++ b/samples/Mercury/expr.moo
@@ -0,0 +1,72 @@
+:- module expr.
+
+:- interface.
+
+:- import_module char, int, list.
+
+:- type token
+	--->	('+')
+	;	('-')
+	;	('*')
+	;	('/')
+	;	num(int)
+	;	('(')
+	;	(')')
+	;	eof
+	.
+
+:- parse(exprn/1, token, eof, xx, in, out).
+
+:- pred scan(list(char), list(token)).
+:- mode scan(in, out) is det.
+
+:- implementation.
+
+:- import_module string, require.
+
+:- rule exprn(int).
+exprn(Num)	--->	exprn(A), [+], term(B), { Num = A + B }.
+exprn(Num)	--->	exprn(A), [-], term(B), { Num = A - B }.
+exprn(Num)	--->	term(Num).
+
+:- rule term(int).
+term(Num)	--->	term(A), [*], factor(B), { Num = A * B }.
+term(Num)	--->	term(A), [/], factor(B), { Num = A // B }.
+term(Num)	--->	factor(Num).
+
+:- rule factor(int).
+factor(Num)	--->	['('], exprn(Num), [')'].
+factor(Num)	--->	[num(Num)].
+
+scan(Chars, Toks) :-
+	scan(Chars, [], Toks0),
+	list__reverse(Toks0, Toks).
+
+:- pred scan(list(char), list(token), list(token)).
+:- mode scan(in, in, out) is det.
+
+scan([], Toks, [eof|Toks]).
+scan([C|Cs], Toks0, Toks) :-
+	( char__is_whitespace(C) ->
+		scan(Cs, Toks0, Toks)
+	; char__is_digit(C) ->
+		takewhile(char__is_digit, [C|Cs], Digits, Rest),
+		string__from_char_list(Digits, NumStr),
+		Num = string__det_to_int(NumStr),
+		scan(Rest, [num(Num)|Toks0], Toks)
+	; C = ('+') ->
+		scan(Cs, ['+'|Toks0], Toks)
+	; C = ('-') ->
+		scan(Cs, ['-'|Toks0], Toks)
+	; C = ('*') ->
+		scan(Cs, ['*'|Toks0], Toks)
+	; C = ('/') ->
+		scan(Cs, ['/'|Toks0], Toks)
+	; C = ('(') ->
+		scan(Cs, ['('|Toks0], Toks)
+	; C = (')') ->
+		scan(Cs, [')'|Toks0], Toks)
+	;
+		error("expr: syntax error in input")
+	).
+
diff --git a/samples/Moocode/hello.moo b/samples/Moocode/hello.moo
new file mode 100644
index 00000000..ba9dda3a
--- /dev/null
+++ b/samples/Moocode/hello.moo
@@ -0,0 +1,5 @@
+@program toy:wind
+this.wound = this.wound + 2;
+player:tell("You wind up the ", this.name,".");
+player.location:announce(player.name, " winds up the ", this.name,".");
+.
diff --git a/samples/Moocode/toy.moo b/samples/Moocode/toy.moo
new file mode 100644
index 00000000..fec09b39
--- /dev/null
+++ b/samples/Moocode/toy.moo
@@ -0,0 +1,19 @@
+@verb toy:do_the_work this none this
+@program toy:do_the_work
+if (this.wound)
+  if ($object_utils:isa(this.location,$room))
+    this.location:announce_all(this.name," ", this:continue_msg());
+    this.wound = this.wound - 1;
+    if (this.wound)
+      fork (15)
+        this:do_the_work();
+      endfork
+    else
+      this.location:announce_all(this.name, " ", this:wind_down_msg());
+    endif
+  endif
+  if (this.wound < 0)
+    this.wound = 0;
+  endif
+endif
+.