Linux didn't kill Sun. Sun killed itself.<p>Low-end servers were coming and anybody could see it back in the mid-90s. Sun instead refused to see it. They focused on the very profitable - for a time - high-end stuff and neglected the other end of the spectrum. After it was brutally obvious this strategy ("stragedy"?) wouldn't work, they decided to make some of the coolest and more expensive x86 boxes money could buy. They made suicidal mistake after 
suicidal mistake.