...the XML that includes the signature or elsewhere. XML Signature 2.0 includes a new transform model designed to addressrequirements including performance, simplicity and streamability. This model is significantly different than in XML Signature...
http://www.w3.org/News/2009.html#entry-8673
...from its inception. Using the most widely accepted standard API functionality as a basis, XGL was developed to addressrequirements for graphics rendering of applications such as electrical and mechanical design and drafting, mapping, animation...
http://pmaillot.chez.com/xgl-wp.pdf