Open source is what works for me. The tools work better. I make my living using the GNU tools, so that's important. Also, as a developer, I feel strongly that nobody knows more about my system than I do. That's why open source is so essential to me in my work.
Open source implies constant peer review.
I've noticed, lately, that I'm not hearing so many complaints about VxWorks and pSOS now that the talk has begun to focus around using embedded Linux. I design embedded systems using open source software and have written two books on the subject. I give source away to everything I've written. The really important questions, that you as a developer need to consider, are . . . We are the experts, and we understand what embedded developers need.