Also known as DSSSL this is a stylesheet language (like XSL or CSS) that is based on SchemeLanguage.
Available DSSSL engines:
* http://www.jclark.com/jade * http://www.oasis-open.org/cover/dsssl.html has a resource on DSSSL.Unfortunately, many of the links on the OASIS-Open page are dead.
We use DSSSL in one of our rendering systems where I work (at a big legal publisher) - it is very nice for generating RTF from SGML, assuming you don't have an allergy to side-effect-free Scheme. There are a number of other output formats you can get out of Jade, but I haven't played with them.
XSL is a descendant of DSSSL and has benefited from it in a number of ways, but is much weaker as a programming language (it's very hard to factor, for one thing). On the other hand I have no problem training rookies on XSL, while DSSSL remains a black art.
There was also a project called OpenJade? at one point which aimed to take up maintenance, as JamesClark? has mainly moved on to bigger and better things. I don't have a URL for OpenJade? but they were doing some interesting things with integrating into Windows Explorer and the like.
OpenJade? is available at http://www.netfolder.com/DSSSL/index.html