The GridShib team from NCSA, Argonne National Laboratory, and the University of Chicago has released the initial beta version of the GridShib software to enable interoperability between the Globus Toolkit (GT) and Shibboleth. The goal of the GridShib project is to allow grids to leverage campus infrastructure to make role-based access control decisions. Typically grids would be required to run their own attribute authorities, which poses a significant burden for many small and medium deployments. This initial GridShib release consists of two plug-ins, one for the GT Web services-based runtime and one for a Shibboleth Identity Provider (IdP). These plug-ins, in combination, enable the Globus Toolkit runtime to query a Shibboleth IdP to obtain attributes about a client, and to make authorization decisions based on those received attributes. The release also includes test applications for verifying the configuration of the Shibboleth and GT installations. The GT plug-in will work with any GT 4.x version of the Globus Toolkit (currently 4.0.1 and 4.0). The Shibboleth plug-in will work against the latest version of Shibboleth, the 1.3b release. For more information about the project, software downloads, and instructions on how to join the gridshib-beta email list, go to the GridShib project site at its Web site.