stelt of http://svg.startpagina.nl says:

As IE doesn’t support SVG natively and all other browsers do, i like your initiative. – stelt

Not sure what SVG is? Wikipedia to the rescue!

Scalable Vector Graphics (SVG) is a family of specifications of XML-based file format for describing two-dimensional vector graphics, both static and dynamic (interactive or animated). The SVG specification is an open standard that has been under development by the World Wide Web Consortium (W3C) since 1999. SVG images and their behaviours are defined in XML text files. This means that they can be searched, indexed, scripted and, if required, compressed. – Wikipedia

You can read what the W3C says about SVG.

Coincidentally, SVG was initially released a month after IE6, so I posted this to both categories.