Highlighter is a PHP class that can be used to reformat highlighted PHP code. It can highlight PHP code and turn keywords into links to the respective manual page in the PHP.net site. If the code is not enclosed in PHP code tags, it adds these tags before highlighting the code. It can also escape a text string to display as HTML using configurable block tags.
AldoContent is a lightweight CMS focused on usability and simplicity. It is designed for multilingual Web sites and can have sections with public and private content. It has file management, is extensible with plugins, and uses gettext for localization. Is written in PHP for a MySQL backend.
WikklyText is a Python-based wiki and modular library for creating custom wikitext rendering applications. Its wikitext engine is compatible with the TiddlyWiki markup language. It functions equally well as a wiki-on-a-stick or as a multiuser wiki behind Apache. It includes a Drupal plugin as well.
Bean is a rich text editor with many niceties added to make writing convenient, efficient, and comfortable. It is, to use a horrible cliché, Text Edit on steroids. It uses Apple's NSText object to do most of what it does, but adds live word count, the ability to adjust printed margins, and lots of other bells and whistles.