Gitit
Gitit is a simple web-based Git repository viewer, written in Rust. It allows you to browse commits and branches in a list of mirrored repositories, and features syntax highlighting for supported files.
Gitit includes a tool for mirroring a set of repositories, which can be used to make backups of ones hosted elsewhere. There is not currently direct support for cloning from Gitit over HTTP(s), and it is not planned to support pushes, either over HTTP(s) or SSH.
Links
You can find Gitit in some of these places on the interwebs: