This is a fork of the awesome MongoAlchemy project, containing a number of new features which are very poorly, if at all documented. Hopefully that will be fixed in the near future.
The fork is at: http://github.com/shakefu/mongoalchemy
A big thanks goes out to Jeff Jenkins (jeff@qcircles.net) as the original creator of MongoAlchemy. The documentation linked to below is the normal documentation for MongoAlchemy.
This project is almost entirely driven by what people need. There are still quite a few things which MA can't do that the standard mongo driver can, but they are largely things which I don't need to do (in particular, I basically never do server-side code execution for performance reasons) and so I don't have as good of a grasp of what the common use-cases are or how to best make them easier to deal with. If MongoAlchemy doesn't do something you need it to, please file a bug/feature request. I'm very responsive and will typically turn around a case within a day or two.