OpenSP is an implementation of the ISO/IEC 8879:1986 standard SGML
(Standard Generalized Markup Language). OpenSP is based on James
Clark's SP implementation of SGML. OpenSP contains the parser nsgmls
and sgmlnorm, spcat, spam, spent, and sgml2xml. Sgml2xml is a tool
for converting from SGML to XML. OpenSP also includes generic API.
Manuals are available in http://openjade.sourceforge.net/doc/index.htm.