Webkit is controlled by Apple, basically. If you want to make big changes (i.e. Chrome) you're going to have to fork it and merge Apple's changes periodically.

Webkit is controlled by Apple, basically. If you want to make big changes (i.e. Chrome) you're going to have to fork it and merge Apple's changes periodically. This will make things harder to maintain, and if you have enough investment, you'll eventually want to fork it (Blink). People don't really use different Webkits - there's Chrome and Safari (incompatible forks) and Opera (declining market share) and that's about it, really. Making all OS' Nix would again be a bad thing, because there'd be no level playing field. The current Unix players are similar in some ways, but have different APIs and behaviours (so OpenBSD has better randomness, Linux has some cool perf monitoring stuff, OS X has its GUI lib) and what you'd essentially find is that there'd be loads of incompatibilities that'd make developing cross-platform a nightmare. Since not all devs run all common operating systems, it'd be hard to motivate fixes. So, you'd develop for one of them, not all - and then you're not in a much better place than the situation with Windows - where you can share a lot of your code cross-platform anyway, or write in a JIT'd language etc.