From the readme:
Linotype is a simple ruby implementation of the Letterpress for iOS game mechanic. Letterpress was created by Loren Brichter and is sold on iTunes. Linotype is meant to be used to write other programs such as simple player command line games, cheating/simulation programs, web-based versions, or whatever else you can think of. My goal is that the community will submit pull requests to this project so that programs can share a common engine.