Rextile allows you to build XHTML documents and entire Web sites with ease. You write text using Textile (a format much more concise than XHTML), automate document parts with Ruby scripting, and generate the site offline (the server gets static XHTML). Rextile was inspired by Xilize. It uses RedCloth to convert Textile to XHTML, erb to run script blocks, and Hpricot for DOM manipulation.
Tartan is a text parsing engine targeted at wiki text. The syntax specification is defined in YAML in the form of regex-based rules. It supports layering and multiple output types. Rules for Markdown to HTML are included, with optional layered extensions for tables. It is implemented in Ruby, but looking to have implementations in other languages.
SiSU (Structured information, Serialized Units) is a lightweight markup based, text structuring and publishing framework (that features granular search). With minimal markup of a plaintext file, it produces: plain-text, HTML, XHTML, XML, ODF, LaTeX, PDF, and populates an SQL database at an object/paragraph level for granular searches. Prepare documents using your text editor of choice, then use SiSU to generate the desired output formats. SiSU is controlled from the command line.
deplate converts wiki-like markup to LaTeX (standard classes, koma, dramatist, sweave), HTML/PHP (single page, chunked/website, HTML, or s5-based slideshow), DocBook (article, book, man/ref page), and really plain text. Currently supported input formats are viki and Ruby's rdoc. The viki markup supports footnotes, citations, index, table of contents, embedded LaTeX for mathematics, integration with R for dynamically generated figures and tables, and more. Output can be customized via page templates.
ZenWeb is a system for building entire Web sites, not just pages. It allows you to focus on the content and the structure of the website, while leaving page construction, markup, layout, and navigation as secondary concerns. It provides tools for complete Web site design and creation, simple paragraph to HTML generation with embellishments, and a rich set of tools for page and Web site creation, modification, and customization.