I recently came across this page (it's a couple years old) detailing an uncommon but interesting migration, from BeOS to OS X.

Okay, so I indulged in a little Schadenfreude against the holy Mac universe from time to time, pissing off thousands. I'm not proud. But neither am I a bad person. I've just always wanted the most from my computer, and it always seemed like the Mac offered very little of the best, and a whole lot of the worst. But recently I've seen the light, and am here to make amends for my blasphemy. I hereby publicly apologize for my past life as a Mac-hater. Not only that, but thanks to OS X, I'm now a bona fide Mac OS lover.

Link