PakLoader is a library that simplifies runtime package loading for Unreal by providing a handful of static functions that abstract Unreal Engine's pak file system.
The simplest function can open a pak file and load its asset registry to your project's given the path to a .pak file and its associated .bin file.
Unreal Engine has a reasonably good package and modding system. Unfortunately, it is largely undocumented, so individuals attempting to use it to load pak files at runtime are left to their own devices (trial and error, mostly) to discover how to get a pak file to load properly.
The documentation for this project is available in the documentation.