This repository contains various files related to "homotopy type theory". Each subdirectory contains a README file which you can inspect to get a description of what is in there.
The repository contains submodules for Vladimir Voevodsky's and Peter Lumsdaine's repositories. You can obtain those automatically by giving the --recursive option when you clone this repository:
git clone --recursive
If you have already cloned this repository without --recursive, you can still get the submodules with
git submodule update --init --recursive