Dwoo is a template engine for PHP5 where you write less and do more. It is mostly compatible with Smarty templates, but it's a full rewrite that builds upon Smarty's syntax to offer more flexibility, both in templates and in PHP extensibility. It also comes with a few adapters for the major PHP development frameworks.
PottyMouth transforms completely unstructured and untrusted text to valid, nice-looking, completely safe XHTML. PottyMouth is designed to handle input text from non-technical, potentially careless, or malicious users. It produces HTML that is completely safe, programmatically and visually, to include on any Web page. You don't need to make your users read any instructions before they start typing. They don't even need to know that PottyMouth is being used.
Kiwi is yet another text to HTML processor which was designed for writing small and medium technical documents and notes. Its markup is very close to the Markdown markup, but Kiwi allows more flexibility in the presentation of your documents. Kiwi is good for writing technical documents, taking notes, or as an engine to be embedded in your application. It has rather complete API documentation.
The docbookm package is contributed with LayManSys and contains very simple XSLT drivers for generating XHTML chunks from DocBook XML. This package does not require an installation; you only have to unzip the package's contents into a directory of your choice and start using it. There is no special documentation available. Use the file abstract.xsl for transforming an abstract and section.xsl for transforming sections. All other .xsl files are only includes needed by those two.