A directory of open source alternatives to proprietary software

I've recently created a curated directory of Open Source alternatives to proprietary software. It's a community driven list so please submit, if you know any good tools to add to the list.

I'm aware there's already a nice competition in the space, but I think most of them list everything that's open source. I focus at picking a solid, well-maintained, for-profit companies that decided to open their codebase to the public.

Enjoy and thank you for your support!