BFD

BFD (Binary Format Description, not Big F***ing Deal) is an XML format based on XSIL (eXtensible Scientific Interchange Language). It is intended to be used to describe file formats, similarly to DFDL; these appear to be two initiatives aiming at the same thing.

Despite the "binary" in its name, BFD can also describe text-based (ASCII) file formats, since text is, after all, one variety of binary data.

Links

 * Page describing BFD