Some weeks ago, Ashot Khachatryan contacted me on this forum with the question if I would be interested in writing a CHIP-8 Emulator in Xojo. I had no knowledge of the system and he had written a good part of an emulator himself. It had some hard to find bugs in it and he was kind of stuck. As it is hard to debug someone elses code, especially if the subject is not very well known, I decided to start from scratch. Or, to say it in Barney Stinsons words, Challenge accepted!
Article and full source code: http://alwaysbusycorner.com/2015/02/20/xojo-chip-8-emulator/