FLOSS Finds

This is a list of some of the interesting FLOSS related C/C++ libraries and programs I've been finding more recently that may not fit under other categories in my software lists. As usual, I prefer cross-platform options that work on a variety of platforms.

Cross-platform screenshot program and library:
https://github.com/rr-/shot/

I've run across some interesting games that I've never bothered to try to build or had to build without the sound because they use a non-Free audio library. FLESSD replaces that option with a compatible API.
https://github.com/darealshinji/flessd

I typically avoid GTK+ libraries. I even removed references to any GTK+ libraries in my forked version of sdcv. However, this looks like an interesting alternative if you're stuck with a program that requires functionality from glib:
https://github.com/iglunix/glibr

Know of some other useful libraries or programs that might aid in building or porting software? Have other FLOSS suggestions? Please let me know about them.