Why should this be included in the repository: It's a C-based game development framework. It appears to be very clean and simple, which is nice when you're talking about game development.
Is it Open Source (yes/no): Yes
How many users do you anticipate will use this software?: I don't know, but it might be niche.
Link to source tarball/zip file: https://github.com/raysan5/raylib/archive/1.7.0.tar.gz