On a similar note, i always wanted to contribute to Firefox, but every time i looked at how to compile it i noped the fuck out of it. It's probably is doable on linux but it's sounds like a nightmare on windows.
Yep. The way you do it on Linux is to grab your distro's package build script and use that. It will specify all of the build- and run-time dependencies (which you use your standard package manager to resolve), and contain whatever commands are required to build it. Usually you just install dependencies and run one command, and you've got a package you can install like any other.
Just install the dependencies listed there, run "makepkg", and boom, Firefox pops out the other end. If you're doing active development, you can probably figure out a quicker change/build/test loop, but that'll get you started.
> but it's sounds like a nightmare on windows.
I wouldn't wish the hell of software development on Windows upon my worst enemy :)