pyPEG is a quick and easy solution for creating a parser in Python programs. pyPEG uses a PEG language in Python data structures to parse, so it can be used dynamically to parse nearly every context free language. The output is a plain Python data structure called pyAST, or, as an alternative, XML.
The GCC XML Tree Node Introspector project consists of a patch to the gcc compiler to output the internal compiler tree nodes in RDF/XML and programs to process that RDF/XML. The tree nodes are complex data structures which represent the source code inside the compiler. Through these tree nodes, users are able to extract information from their programs that would be otherwise very difficult to obtain. Modules exist to store these nodes in Redland RDF using a Berkley database. The long-term goal of the project is create a high-level API that will make the programmatic manipulation of programs easier than it is now.
Ciao is a complete Prolog system subsuming ISO-Prolog with a novel modular design which allows both restricting and extending the language. Ciao extensions currently include feature terms (records), higher-order, functions, constraints, objects, persistent predicates, a good base for distributed execution (agents), and concurrency. Libraries also support WWW programming, sockets, and external interfaces (C, Java, TCL/Tk, relational databases, etc.). An Emacs-based environment, a stand-alone compiler, and a toplevel shell are also provided.
ANTLR (ANother Tool for Language Recognition) is a language tool that provides a framework for constructing recognizers, compilers, and translators from grammatical descriptions containing C++, Java, or Sather actions. It is similar to the popular compiler generator YACC, however ANTLR is much more powerful and easy to use. ANTLR-produced parsers are not only highly efficient, but are both human-readable and human-debuggable (especially with the interactive ParseView debugging tool). ANTLR can generate parsers, lexers, and tree-parsers in either C++, Java, or Sather. ANTLR is currently written in Java.