OK, so why have Novell, Xandros, and Linspire all gotten into bed with Microsoft? Is it...

1. They were seduced by Steve Ballmer's charming smile?
2. They've gone over to the dark side of the force?
3. Terror of Microsoft's mighty patent portfolio had them groveling at Microsoft's feet?
4. It actually makes business sense to give their customers some level of Microsoft software compatibility?