Advent is a graphic adventure game engine similar to Monkey Island or The Longest Journey. It uses guile-goops as its extension language to create and manage the object interactions and C++ for all the low level stuff.

Two demo-games are provided (retriever, cosmos).

License: free

Additional System Requirements: You need Guile, Goops and ClanLib when you compile from source, but no extra libraries are requirements when you use the static binary.