There is also a project (probably many) for managing patches and/or issues in a git repository, but I can't find any links to it right now (can't access my github stars...)
Edit: there is also a alternative to git that has much of the same functionality of github embedded in the SCM itself, Fossil. https://www.fossil-scm.org
Edit2: GitHub back, think the project I was thinking about above was https://github.com/MichaelMure/git-bug which describes itself as "Distributed bug tracker embedded in git"
The nice thing about BE compared to the more recent ones, is that it's VCS agnostic - it's just files in the repo, rather than e.g. using some special metadata feature of git/etc to track the issues.
I've yet to see a web UI for it tough (to expose it to non-technical users).