diff --git a/backend/src/langs.ts b/backend/src/langs.ts
index 07e03d4..9a54cf1 100644
--- a/backend/src/langs.ts
+++ b/backend/src/langs.ts
@@ -1308,6 +1308,14 @@ func main() {
     main: "main.gs",
     run: "golfscript main.gs",
     template: `'Hello, world!'
+`,
+  },
+  grass: {
+    name: "Grass",
+    main: "main.grass",
+    run: "grass < main.grass",
+    hello: `w`,
+    template: `wWWwwww
 `,
   },
   groovy: {
diff --git a/scripts/docker-install-phase4.bash b/scripts/docker-install-phase4.bash
index b1f6a59..dfbd79a 100755
--- a/scripts/docker-install-phase4.bash
+++ b/scripts/docker-install-phase4.bash
@@ -165,6 +165,10 @@ rm -rf go
 wget -nv http://www.golfscript.com/golfscript/golfscript.rb -O /usr/local/bin/golfscript
 chmod +x /usr/local/bin/golfscript
 
+# Grass
+wget -nv http://www.blue.sky.or.jp/grass/grass.rb -O /usr/local/bin/grass
+chmod +x /usr/local/bin/grass
+
 # Haskell
 curl -sSL https://get.haskellstack.org/ | sh
 wget -nv https://github.com/raxod502/riju-cdn/releases/download/brittany-0.12.1.1/brittany -O /usr/local/bin/brittany