This is a post aming to show you some open source games, you can start hacking on today. I think open source games, among other things, have a huge advantage in that they probably will outlive their commercial counterparts. As the availability of many AAA games are more-or-less tied to cloud gaming platforms, it is becoming increasingly important that we have these alternatives.
Below you'll find some of my favorites. Maybe you already know them? If you're working on your own game and/or looking for contributions, feel free to add it in the comments.
(Gitlab link at the bottom of the page)
Fellow dev.to user Thamara Andrade has made a great article on how to contribute to Open Source, you can find it here:
Wikipedia is a great source: https://en.wikipedia.org/wiki/List_of_open-source_video_games