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.
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.