This is a prototype for an SGML-based litterate-programming tool.
The ydSLitProg file-format is defined as an extension to the popular docbook DTD. Sgmlspl spec files are used to convert ydSLitProg files into input files for existing litprog tools - this helps ensuring the DTD is useful and generic enough for what we want.
When the DTD will have been enough validated using such tools, work on tangler and weaver will be ready to begin.
Note that I originally named ydSLitProg as SWEB, but that name is already taken by a TEI-based DTD and litprog tool.
Get it from here.