diff --git a/README.md b/README.md
index 868ca71..9770f63 100644
--- a/README.md
+++ b/README.md
@@ -110,3 +110,4 @@ docs/                # Original game manuals, maps, and story file (.z5)
 ## Additional information Infocom Games
 
 - Library of all Infocom games https://eblong.com/infocom/
+- Open source Z-file game engine: https://gitlab.com/DavidGriffith/frotz