The bottom line: Microsoft Office Communications Server 2007

Microsoft
Overall score: Good, 7.2/10
Ease-of-use: 7/10
Features: 8/10
Scalability: 8/10
Management: 6/10
Security: 7/10
Value: 6/10
Cost: Base server license is US$2,790 plus US$697.68 for one year of Software Assurance; Standard and Enterprise client access licenses are US$487.56 with another US$121.92 for one year of Software Assurance
Platforms: Windows Server 2003 with SP1 or Windows Server 2003 R2; Office Communicator 2007 client supports Windows 2000, Windows XP, and Windows Vista
Bottom Line: Office Communications Server 2007 is a highly functional and oh-so-slick communications platform that combines IM, conferencing, presence management, and VoIP telephony. Smooth and useful integration with Exchange Server 2007 and SharePoint Server 2007, and with Outlook and Office clients, make this a top choice for well-heeled Windows-centric enterprises.

The Bottom Line: Microsoft Exchange Server 2007

Microsoft
Overall score: Good, 7.5/10
Ease-of-use: 6/10
Features: 8/10
Scalability: 9/10
Management: 7/10
Security: 8/10
Value: 6/10
Cost: Standard server license costs US$699; Enterprise Edition costs US$3,999. Standard client access license costs US$67; Enterprise client access license costs US$25.
Platforms: Windows Server 2003 with SP1 or Windows Server 2003 R2
Bottom Line: Exchange Server 2007 marks a big change from Exchange 2003. Almost all facets of the platform have been improved, especially security, high availability features, and Web access. The new Clustered Continuous Replication alone will tempt large shops to upgrade, while the Unified Messaging role and Office Communications Server 2007 integration are also interesting. These improvements do come at a cost of a whopping learning curve for administrators.