This is a BOSS thread, let's see what turns out to be our favorite open source software. For me, it's definitely GIMP, the gnu image manipulation software. You can get it at http://www.gimp.org/
I dislike OSS, especially those projects I'm personally involved in developing. Someone will always come up to you and tell you - ``Hey man, your software is shit, it crashes like every minute, man!'', even though his kernel is broken, his userland environment alpha quality and other software packages crash frequently on his machine. I'm talking about FC-16 alpha - fuck you, Fedora.