Python API to Mercurial using the command-line interface
hgapi is a pure-Python API to Mercurial, that uses the command-line interface instead of the internal Mercurial API. The rationale for this is twofold: the internal API is unstable, and it is GPL.
hgapi works for any version of Mercurial, including < 1.9, and will instantly reflect any changes to the repository. It also has a really permissive license (do whatever you want, don’t blame me).
For example of code that uses this API, take a look at https://bitbucket.org/haard/autohook which now uses hgapi exclusively.