These two official documents are maintained by the OASIS consortium:

• 15695.pdf − XRI 2.0 FAQ Copyright © OASIS Open 2005
• 17293.pdf − XRI 2.0 Resolution Copyright © OASIS Open 2006

The following websites are primary sources of information about XRI:

• http://www.inames.net/: The site of the global XRI root authority, with a proxy resolver and information about i-brokers.
• http://en.wikipedia.org/wiki/I-name: Wikipedia article about i-names.
• http://www.oasis-open.org/: The company behind the XRI standard (and others).