Round 7: Microsoft software compatibility
It's a truism in Windows circles: The Microsoft Office team charts its own course. As the drivers behind the company's longest-lived cash cow, the Office folks have the luxury of being able to ignore the hemming and hawing of the Windows team and to choose to support whatever platforms make business sense. In the case of Office 2007, this meant eschewing any exclusive tie-ins to the perennially delayed Vista. As a result, the latest version of this bovine ATM works equally well under both Windows XP and Vista, much to the chagrin of the guys on the other side of the OS Chinese wall.

It's a similar story with Microsoft's BackOffice product line. There are few, if any, advantages to deploying Vista as a client to Microsoft Exchange, Microsoft SQL Server, or Microsoft SharePoint. As the gatekeeper to many of these resources, Microsoft Office often serves to level the playing field. And as I just noted, the current version of Office – Microsoft Office System 2007 – runs great on Windows XP.

What about future versions? There's no doubt that, eventually, Microsoft may try to target Vista exclusively. However, finding features and functions that Vista supports and XP doesn't is not as easy as it sounds. Remember, much of Vista's "newness" is only skin deep. In fact, outside of DirectX 10 – which is exclusively a Vista technology – there's no valid reason for excluding XP from the supported platforms list of any new application.

Of course, this may change come Windows 7, the feature set of which is still very much in flux. However, nobody's arguing that you should stick with XP forever – just that you can stick with it for now and potentially skip a Windows generation without incurring any real pain.

Decision: Windows XP is still, and likely will remain for some time, the compatibility bar for new Microsoft applications. If and when Microsoft attempts to create an exclusive Vista tie-in, the company will need to articulate some valid technical reason – one that stands up to scrutiny from the IT community – for not supporting Windows XP.

Round 1: Security
Round 2: Manageability
Round 3: Reliability
Round 4: Usability
Round 5: Performance
Round 6: Hardware compatibility
Round 7: Microsoft software compatibility
Round 8: Third-party software compatibility
Round 9: Developer tools support
Round 10: Future-proofing