Hgfs is a read-only filesystem interface to Mercurial repositories. The interface gives access to the commit message, manifest, and files of each revision, and to .tgz's of each revision (the .tgz's are generated as they are read). The filesystem is a front-end for the Mercurial library that comes with it. All code is written in Limbo, for Inferno.
repos-tools is a set of command-line utilities to make work on your code repositories faster and easier. It lets you push, pull, build, and do other things on your repositories all at once. The supported (D)VCSes are Git, Subersion, Bazaar, and Mercurial. For GitHub users, forking, following, watching, and dealing with issues can be done from the shell.