[dromey]

GPL is essential when you are hacking your own stuff because the last thing you want is for someone to take what you've done, improve it, sell it and then close it off...and Linux is GPL. BTW, GNU stands for GNU is Not Unix, which comes from the fact they had to rewrite AT&T's Unix utilities from scratch.

Windows is great for earning money precisely because it is so deeply flawed and requires so much support. It's an endless money pit for the people deploying it, and a guarantee of lifetime employment for you. I've hacked on systems like Windows that were closed source and unfree, and it was not rewarding except in money terms.