specifically the two biggest douches, Apple and Microsoft:

http://www.dailytech.com/article.aspx?newsid=17863

it's an interesting read and gives you a glimpse at just how these two (and others like them) use their size to try and stamp out any competition.

personally i have always like Solaris and thought that with just a bit of adjustments it could be a viable contender on the desktop, it's too bad that the powers that be at Sun have decided that they would rather target the server markets.