[Discover] RELAX NG Specification http://www.relaxng.org/spec-20011203.html
(schema xml relaxng reference) 
[Discover] XML Schemas: Best Practices http://www.xfront.com/GlobalVersusLocal.html (xml schema patterns schemas)
[Discover] RELAX NG Tutorial http://www.relaxng.org/tutorial-20011203.html (relaxng schema standards xml)
[Discover] RELAX NG home page http://www.relaxng.org/ (schema programming xml relaxng)
[Discover] GridForge: Project Summary - DFDL-WG http://forge.gridforum.org/projects/dfdl-wg/ (grid metamodelling schema xml)
[Discover] Extending and Versioning Languages: XML Languages http://www.w3.org/2001/tag/doc/versioning-xml (versioning schemas xml)
[Discover] XML Schema Upgrade Service (PR version) http://www.w3.org/2001/03/webdata/xsu (devtools schemas xml)
[Discover] XML Schemas: Best Practices http://www.xfront.com/GlobalVersusLocal.html (xml schema patterns schemas)
[Discover] RELAX NG Tutorial http://www.relaxng.org/tutorial-20011203.html (relaxng schema standards xml)
[Discover] RELAX NG home page http://www.relaxng.org/ (schema programming xml relaxng)
[Discover] GridForge: Project Summary - DFDL-WG http://forge.gridforum.org/projects/dfdl-wg/ (grid metamodelling schema xml)
[Discover] Extending and Versioning Languages: XML Languages http://www.w3.org/2001/tag/doc/versioning-xml (versioning schemas xml)
[Discover] XML Schema Upgrade Service (PR version) http://www.w3.org/2001/03/webdata/xsu (devtools schemas xml)