I build open source computer games using a custom made engine.
YCatSim is a cat simulator currently in very active development and for "pay what you want but it's free"-sale here soon. You are a cat doing cat stuff (destroying things, following red dots while destroying things, destroying accidentally scratching people in a very cute manner till they bleed to death). Did I mention I own two cats (or do they own me)? Yeah, guess what they're doing pretty much all the time...
YAFANWEBATPC is a MMORPG/sandbox (you can do pretty much whatever you want, there will be even spaceships. built by you ingame.crashed into a rock. and flying to distant worlds.) currently in "closed pre-alpha" (which means nothing really works like I want it yet, so I'll hopefully fix that up soon).
YDestination is the online service holding it all together (think of steamcloud without the sucking part). Still not doing very much, it'll be used for account management, chat, DLC & mod management, etc in my games.
and, of course, YEng, the one engine to rule them all, one engine to find- oh. no. but I bet it powers those projects. And you can use it too, of course. If there's any questions about that, just ask me.