Submission: zstd

[felixhandte]

Zstd is a widely-deployed, state-of-the-art compression algorithm. Although the library is developed in many source files (so as to, among other things, allow inclusion of different subsets of functionality), there is tooling to create a single compilation unit version of the library. Admittedly, it's not tiny, but it depends only on libc, and even that dependency is optional.