This directory contains libraries that are used in and/or customized by Theseus but are considered "third-party". The general idea is that these libraries are not Theseus-specific and could be refactored out into their own standalone projects easily.
As such, and most importantly, libraries in libs/ must not depend on any crates in the Theseus kernel (in kernel/).
Some of these folders are git submodules (separate repositories), while others are included directly in the main Theseus repository itself.