This is binary-data, consisting of a domain-specific language for describing binary protocols, which generates readers and writers into a high-level object.
The overall goal is to be able to write definitions of binary data in an easy to understand manner.
This project used ideas from the defstorage system available as part of the Genera Common Lisp operating system.
The documentation for this project is viewable online at http://opendylan.org/documentation/binary-data/.
There are two papers about this project: