Ikiwiki is a wiki compiler. It converts wiki pages into HTML pages suitable for publishing on a website. Ikiwiki stores pages and history in a revision control system such as Subversion or Git. There are many other features, including support for blogging, as well as a large array of plugins.
PMPU is oriented around the typical "Push / Pull" workflow of distributed SCMs; as such it is designed to make it easy to see what changes are arriving from remote repositories and what changes are due to be pushed upstream. It also has support for creating changeset bundles and for importing both bundles and patches; these are primarily useful when interacting with the development process via e-mail. Rather than re-invent the wheel, PMPU can make use of external history views and commit tools. For mercurial repositories, I recommend the 'hgk' or hgview viewers and the excellent Qct commit tool.
Extensible and Modular Generics for the Masses (EMGM) applies concepts of datatype-generic programming to define generic functions for supported datatypes using type classes.