This is a community wiki post, everyone with trust level 1 or higher can contribute here with new content. Please only add open-source software to the list. Also have a look at this and this overview of open-source alternatives.
- Signal the privacy oriented messaging application, open source, cross-platform.
- Inkscape, vector graphics editor
- OBS (Open Broadcaster Software), cross-platform screen recorder.
- Linux MultiMedia Studio https://lmms.io/
- Mastodon Follow friends and discover new ones.
- Crop Rotator - my program for complex rotation plans management (demo)(help appreciated) source code
- Farhacks software - software bookmark of farmhacks project.
- GNOME is a free and open-source desktop environment for Unix-like operating systems.