StatusNet Desktop is a dedicated multi-platform client for connecting to StatusNet messaging servers (requires a server running 0.9.3 or later). The client can connect to multiple StatusNet sites to read and post updates, including secure and private installations. Home, public, individual, and group timelines can be read and posted to, as well as direct user-to-user messages and keyword searching of the public notice stream. Support for StatusNet-specific features such as user groups is explicitly included, where these are usually not supported by generic Twitter-API clients.
Chouwa is a library that aims to ease the integration of Jinja2 into Django projects. It does this by providing equivalents of some of django's helper methods that depend on its template subsystem, as well as providing built-in globals and filters and providing a mechanism for user applications to introduce their own globals and filters.
Sputnik is a content management system (CMS) designed for extensibility. It works as a wiki out of the box, but can be extended into other things. It offers editable nodes, history and diff, user accounts with optional email validation, a flexible permission system, RSS feeds, and more. Sputnik supports access control and has editable templates. It can be used to maintain a personal Web site that doesn't look like a wiki and that only you can edit. Sputnik is easy to install on shared hosting without root accounts.
PHP Template Inheritance consists of a handful of functions which allow child templates to inherit common structure from base templates. Multiple levels of inheritance are possible. The inspiration for this project was Django's template inheritance mechanism. Templates are PHP files too, so you can do (almost) whatever you want in them.
pyratemp is probably (one of) the smallest complete template-engines for Python (with about 500 LOC). It has a very small set of special syntax in the templates. This reduces complexity and the probability of bugs and lead to an easy-to-use and intuitive user-interface. It uses embedded Python-expressions (in a "sandbox"), is well documented, has full Unicode-support, and produces very good error-messages, which is very useful when creating new templates.