Varnish
This is not any project, the very day someone (LITERALLY) dumped this Varnish thing on my desk I went from WTF to a software architecture slap in the face.
I remember feeling humbled when I first worked on a project used by 500 offices across France, and getting the same feeling on a project used by 3000 offices after that, and later on I worked on a project that would touch million of peoples. The same thing happened with Varnish: to better understand the internals I wrote and published a module and got my first “users”: both scary, great, and humbling.
Then I got involved a bit more with the project and joined Varnish Software, became part of the core developers team and since then I have been contributing features, documentation, bugs and bug fixes on a regular basis. This project turned upside down many “best practices” I had adopted before that.
Web site: https://varnish-cache.org/
Hitch
Another project sort-of under the Varnish umbrella. It’s a fork of Stud aka the Scalable TLS Unwrapping Daemon. The Stud project is now abandonware and recommends Hitch as a replacement.
When Hitch branched off Stud, besides the renaming work that is expected in the code base, the first big task was to clean up the code to match the coding standards from Varnish Cache. Very pleasant coding standards to work with.
I don’t contribute much to Hitch, and the main thing I’ve done is a complete rewrite of the test suite to make it slightly easier to maintain in the future. And since the test suite is written in POSIX Shell, I very much enjoyed the challenge.
Web site: https://hitch-tls.org/