Jade is James Clark's implementation of DSSSL -- Document Style Semantics and Specification Language -- an ISO standard for formatting SGML (and XML) documents.
OpenJade is a project undertaken by the DSSSL community to maintain and extend Jade, as well as the related SP suite of SGML/XML processing tools. OpenJade and OpenSP are distributed under the same license as Jade.
The OpenJade development effort is hosted at SourceForge.
Mulberry Technologies' website has much in-depth information on DSSSL.
Didier PH Martin maintains a DSSSL/OpenJade Home Page
Braifo is Peter Nilsson's Braille backend for OpenJade.
Feel free to send comments, feedback, bug reports, etc, to the OpenJade mailing list. This list covers issues about both OpenSP and OpenJade.