Libs

The Libs subsystem contains additional libraries that were developed alongside OpenMW for a while and have been reintegrated since then.

Mangle
An abstraction layer for 3rd party libraries. Originally OpenMW was supposed to get a very strong abstraction towards 3rd party libraries for sound, GUI, physics, rendering and as such, which would have made switching out these libraries very easy. This concept has only been implemented in a few cases (it proved to be useful for the sound implementation though) and has been abandoned since then. OpenMW will continue to use Mangle but Mangle is unlikely to receive any further improvements.

OpenEngine
A library that was meant to be build from OpenMW-independent re-usable game engine parts. This concept has been abandoned since then. OpenMW will continue to use OpenEngine, but OpenEngine is unlikely to receive any further improvements.

Platform
A semi-redundant collection of portability-workarounds. We should probably get rid of it at some point.