The little known application 'MTG Forge' has existed for a few years, it is a Java application (meaning it can be run on Windows, Linux, or Mac) and it provides a Magic playing AI to play against. The AI is far from perfect, but it is further along than almost any other project (except Wizards' own Xbox game,) and the system has several thousand cards programmed into it. In short, it's a fun side project. Today the application's blog announced that due to Wizards' lawyers the name has officially been changed to 'Forge.'
The original blog post:
The name "MTG Forge" appears to attract Wizard's lawyers like flies to Aunt's Mays apple pie. Having the initials "mtg" seems to be the reason for the cease and desist letter about my original Sourceforge.net site. The name "Forge" sounds a little weird and empty to me but it is good enough. (And everybody by now should know that I am a firm believer in “good enough”.) The official name of this project is "Forge" and my official nickname is "mtgrares".