Work in a specific area can be triggered by a W3C Advisory Committee member submitting a specification to the Consortium for consideration.
Web Schematics
At the January 1998 W3C Advisory Committee in San Jose, Rutherford Appleton Laboratory and INRIA agreed to submit an XML-based vector graphics working draft to W3C. As INRIA were the W3C Host in Europe, the submission was made by the Rutherford Appleton Laboratory. This was called Web Schematics and was heavily influenced by pic. It was a constraint-based graphics system.
At the same time as putting forward the submission, a prototype implementation of the proposal was developed for the W3C Reference Browser, Amaya. This was first demonstrated at W3C meetings in Bonn and Utrecht and later at the WWW7 Conference in Brisbane, all in April 1998.
PMGL
10 days after the RAL/INRIA submission, Adobe and partners put forward a submission Precision Graphics Markup Language (PGML), a 2D graphics language designed to satisfy both the Web's scalable lightweight vector graphics needs and the precision needs of graphic artists based on the PDF/PostScript imaging model.
As with Web Schematics, PGML was defined as an application of XML.
PGML followed the imaging model closely but was quite verbose in its description of paths. It was at a lower level than Web Schematics in the graphics pipeline. It also had the Y-axis pointing downwards, like many of the very early graphics systems but not the international graphics standards.
VML
13 days after the Web Schematics submission, Microsoft and partners put forward a submission Vector Markup Language (VML). This was a well-formed proposal with pilot implementations that worked well with HTML and CSS. It had a much more concise path notation than PGML and some impressive formula definitions of paths.
These three submissions were the ones that caused W3C to propose a Working Group (WG) be established to look at an XML-based Recommendation for 2D vector graphics on the web.
There was never a submission from WebCGM for an XML-based version, which is surprising especially as CGM Open discussed the relevance of the WebCGM profile versus PGML.
There was a much later submission from Excosoft for a Java-based DrawML as a 2D scalable graphics language designed to facilitate the creation of simple technical drawings.