> An example of this is Quicksilver on the Mac. It's considered to be one of the best Mac apps ever and the developer who made it, decided to open source it after he decided to take a job at Google. Quicksilver development fell apart afterwards.

I don't use a Mac, and don't even know what Quicksilver was until I checked, but this was posted 17 hours ago:

http://blog.qsapp.com/post/27644282840/ss69-release-quicksil...

Maybe development didn't follow at the same pace as before, but to say it "fell apart" when they are very close to releasing 1.0 seems not very accurate to this outside observer.