> Are Mozilla paying for people to do these experiments or is it people sending patches? I don't know but I'd imagine a lot of it is the latter.
As far as I'm aware, it is mostly developed by Mozilla employees, but heavily used for new devs to get their feet wet. Not only is it not mission-critical when they make mistakes there, they also get a ton of feedback on their work.
Have you tried a recent Nightly? Firefox is getting faster: http://www.techradar.com/news/firefoxs-blazing-speed-with-hu... [1]. As Mozilla continues to pull in code from Servo and implement e10s, Fiefox will perform better and crash less.
[1] discussion: https://news.ycombinator.com/item?id=14848836