Wikipedia
The Sweble Wikitext parser is an open-source tool to parse the Wikitext markup language used by MediaWiki, the software behind Wikipedia. The initial development was done by Hannes Dohrn as a Ph.D. thesis project at the Open Source Research Group of professor Dirk Riehle at the University of Erlangen-Nuremberg from 2009 until 2011. The results were presented to the public for the first time at the WikiSym conference in 2011. Before that, the dissertation was inspected and approved by an independent scientific peer-review and was published at ACM Press.
Based on the statistics at Ohloh the parser is mainly written in the Java programming language. It was open-sourced in May 2011. The parser itself is generated from a parsing expression grammar (PEG) using the Rats! parser generator. The encoding validation is done using a flex lexical analyser written in JFlex.
A preprint version of the paper on the design of the Sweble Wikitext Parser can be found at the projects homepage. In addition to that, a summary page exists at the MediaWiki's futures.