Cheetah is a template engine and code generation tool, written in Python. Web development is its principle use, but Cheetah is very flexible and is also being used to generate C++ gamecode, Java, sql, form emails and even Python code.
Frosttie (FROnt-end SchemaTron Text Internet Engine) takes XHTML pages and processes them with various user-definable filters such a W3C's WAI, Section 508 (US) web usability compliance, ad removal, etc. It can be used with zKnowMan.