I've tried Cygwin, and found it to be cumbersome. It was a few years ago, but if I reebmemr correctly, I had a hard time compiling anything really useful on it, and it was a system hog.For the past year or so, I've been using coLinux, and adore it! At one point at work, I thought we had hit a bug in replication, and so created multiple instances of coLinux within my PC, installed the same version of MySQL we had on our production servers, configured circular replication, and started mucking around to see if I could recreate the problem we had. Sure enough, I did (and subsequently filed a report). I typically have coLinux running at all times in the background, and find that when it isn't doing anything, it really doesn't affect system performance (I play EQ2 and EveOnline, and don't bother stopping the coLinux daemon). I haven't tried running Xwin in coLinux, but I don't have any reason to I use it for development, as a local test server which I can break and reinstall without worry (reinstallation is as simple as copying the image file I made before I broke it).I haven't tried VMWare, but I'm pleased with coLinux.