Warning
githome has been superseded by gogs (see http://gogs.io), which has acceptable performance on a Raspberry Pi 2 at least, even though it lacks the SSH -> C -> git speedup implement by githome.
githome is an authorization system for hosting git repositories. It allows to create rules for different users, such as a read-only or developer access and makes it easy to create new repositories by simply pushing, without having to prior create them.
githome is somewhat similar to gitolite, the successor to gitosis. It aims to be a little more self-containted and easier to install and administer -and it's written in Python instead of Perl. The main difference is that it uses a command-line interface and database to handle settings instead of a git repository, making setups more self-contained and migrateable.
As it was born out of frustation of the bloat of gitlab (and the resulting slowness and painful installation), it places a premium on speed. It is measured against its ability to run on a first-generation Raspberry Pi (the single-core, 512 MB RAM kind).
Since it is a security-sensitive piece of software facing the outside world, detailed information about its structure is found in the documentation, to help anyone administering it understand the implications on the systems security.