Parser & Generator
Another C++ based JSON Library (/w Parser/Generator/Navigator)
C#Prolog -- A Prolog interpreter written in managed C#
A LALR(1) Parser Generator for JavaScript written in JavaScript
Parser Generator based on Coco/R
A PEG based parser generator, with advanced features
A multi-language port of Browserscope's user agent parser
Recursive descent parser generator for php.
A packrat parser generator for C
Object Oriented Parser Generator
Java lexical analyzer generator
UML 2 Statemachine for C++ is a development framework with DSL support
Mini Python Compiler written in Java