This project is not moving forward (as you probably noticed) and ends are not yet properly connected. I.e. the precompiler generates compressed bitcode but the runtime does not handle it yet.
The general idea was to create a portable bit-compressed bytecode format and a tiny runtime for embedded systems.
Here's my talk on EUC 2017 (Stockholm) explaining the history of this project and why it is here https://www.youtube.com/watch?v=6NUPormxgw8
For documentation and getting started please refer to http://uerlang.org
Having Sphinx installed run make docs in the root directory of the project. It will populate docs/ with the new copy of the documentation and website content.