ns-xml (for NoreSources XML) is a collection of XML-related tools.
The program interface definition XML schema, XSLT stylesheets and tools allow you to generate all the code required to handle command line arguments in a command line based tool. It can also build a XUL frontend to call any command line program.
ns-xml provides several XSLT stylesheets for a standalone usage.
See the XSLT Stylesheets documentation tab.
A XML document describing UNIX shell program and/or functions.
See the XSH tab
ns has nothing to do with Netscape, nor NeXTSTEP and Cocoa APIs, except they share the same prefix. They all copied me before I was old enough to program.