Most of these already have a Windows and Mac version. Blender, the very best movie quality animation software in existence. OpenCV SDK, a toolkit for "Computer Vision" for teaching cars to "see and drive themselves". (has a Windows and Mac version). Grisbi accounting software...IMHO better than QuickBooks. Ruby, Ruby on Rails, Hobo, all used together for website design of database centric websites.
Soon there will be a new scheduler for all versions of Linux in the 2.6.38 kernel that will far outperform any version of Windows that now exists and probably will ever exist!

Time to start investigating!

Arthur