[mschuster91]

> I know the situation sucks on Windows,

It sucks on Linux even more. On Windows, at least everyone (including the build tools) is used to shipping dependencies, on Linux not so much.

You have all sorts of crazy dependencies on (system) libraries (not to mention libc versions), and you probably don't want to fool around with dozens of package managers (apt-get, rpm, whatever Gentoo is using, hand-rolled distros), and you pretty much don't want to store stuff in /usr/local because you might overwrite stuff already present there.

> but on Mac, why not use the system WebKit framework?

Because Chrome is far faster to pick up new stuff than Safari. Also, most people these days prefix and test only for Chrome, which disqualifies embedding a Firefox runtime.