https://github.com/libsdl-org/SDL
https://github.com/libsdl-org/SDL_image
https://github.com/libsdl-org/SDL_ttf
https://github.com/compuphase/minIni
https://github.com/grassator/bdd-for-c
https://github.com/PortMidi/portmidi
https://github.com/EsotericSoftware/spine-runtimes
https://github.com/Chunde/getopt-for-windows
https://libwebsockets.org/repo/libwebsockets
https://github.com/openssl/openssl
https://www.sqlite.org/download.html (use SQLite amalgamated source code, unpack into `sqlite` directory)
https://code.modal.sh/TheoryOfNekomata/bdd-for-c-mocks
git://git.alsa-project.org/alsa-lib.git (linux/unix)