Actually there are plenty of Unix flavors. Sun, HP/UX, IBM etc. All Linux will do is replace IBM UNIX and may be HP/UX. SCO UNIX already adapted Linux because they could not compete with the bigger guys. Will Linux be a desktop client? We already have one good one called Mac OS. I predict the way Mac is going - finally they will give Microsoft a run for money in the OS market. But other software for Mac? It will be still be Microsoft.