Virtual Server 2005 R2 (x64) Enterprise Edition 180 Day Evaluation
http://www.microsoft.com/downloads/details.aspx?FamilyId=44E55F58-993C-4D59-8143-87F9C656A1A1&displaylang=en

Virtual Server 2005 R2 (x86) Enterprise Edition 180 Day Evaluation

http://www.microsoft.com/downloads/details.aspx?FamilyId=803FF21D-0C62-453D-8696-7894BB549CBD&displaylang=en

Virtual Server 2005 R2 VM Additions
http://www.microsoft.com/downloads/details.aspx?FamilyId=A963433C-193B-41AC-AF6E-AB7AB2DB8541&displaylang=en

Virtual Server 2005 R2 Host Clustering Whitepaper
http://go.microsoft.com/fwlink/?LinkId=55644

Improving IT Efficiency at Microsoft with Virtual Server
http://www.microsoft.com/downloads/details.aspx?FamilyId=25DCB14A-03F5-434D-83F7-4D46C1675B87&displaylang=en