Here is a recursive descent parser generator, written in Common Lisp.
It generates the scanner and parser in lisp, or in a pseudo-basic. It is possible to add generation of the parser in other programming languages.
Note: those are old files, an ancient version of RDP. For real uses, get the current sources from gitorious; the RDP Generator is now included in the com.informatimago repository:
git clone https://git.gitorious.org/com-informatimago/com-informatimago.git
or you can just get it with quicklisp: