> It is a portable, cross-compilable, installable, packageable fork of NaCl, with a compatible API, and an extended API to improve usability even further.

> Sodium supports a variety of compilers and operating systems, including Windows (with MingW or Visual Studio, x86 and x64), iOS, Android, as well as Javascript and Webassembly.

Look at the release notes on the releases page to see what kind of things they do.

https://github.com/jedisct1/libsodium/releases