If you are involved with US government contracting, you are likely aware of The Common Criteria Evaluation and Validation Scheme for testing the conformance of IT products to a set of security standards. Today Microsoft announced that Windows Server 2003, Windows XP, Windows XP Embedded, and Windows Server 2003 Certifcate Server have achieved Common Criteria (CC) Evaluation Assurance Level (EAL) 4 + Augmented with ALC_FLR.3 certification. More details by following the links.