SEUL.org: "There has been a lot of effort in the last two weeks around Michael Williams's idea of an open source version of the Schools Interoperability Framework (SIF) Zone
Information Server (ZIS). To recap, the SIF is an XML schema proposed by a consortium of software vendors to allow compliant programs to exchange data. The ZIS is a "gatekeeper"
program that registers the application programs as to what type of data they provide (each "type" can be registered to only one app at a time)."
February 5, 2002