The example given is of the definition that originated with the Liberty Alliance.
Here's an elaboration of the other concept of federated identity that has appeared in the Internet2 community and elsewhere. The higher education federation (for example) is a group of organizations (universities) that agree to accept and trust each other's local authentication process. That is, each university manages the credentials of its own population but also needn't manage the credentials of potential visitors form elsewhere.
Federation is something that organizations do; they join a federation. They agree about some things (e.g. that they will trust each other), but also agree to disagree about other matters (e.g. precisely how the credentialing process is performed at each institution and precisely how cerdentials are verified at each institution.
The Liberty Alliance definition is really more about something that users do. Each user agrees that their identity information can be shared among organizations of their choosing.
I suggest removing this link at the end: "Federated Identity Primer" It now requires setting up an account with Ping Identity Corporation. Vexar theoriginal 15:07, 30 October 2007 (UTC)
I suggest linking information about Eduroam - the federated identity system in use in Europe, Australia and Canada —Preceding unsigned comment added by 126.96.36.199 (talk) 12:57, 15 October 2008 (UTC)