Vista Compatibility: What Does Microsoft Owe Us?

Opinion: What is the real compatibility picture for Windows Vista? It's hard to tell with no public sighting of a compatibility list. Microsoft is pushing virtualization-but the acceptance of that approach remains to be seen. Still, some say M

Despite the rosy outlook sounded by Windows Vista true believers, the compatibility picture for Vista is blurry at best. How Microsofts next-generation operating system will deal with the data and apps of previous generations must be near the top of the transition checklist for IT managers.

At the same time, other voices with long experience in the industry ask if the Vista rollout really has to be done this way? They predict that the day may be coming when customers stand up and yell that theyre not going to take this anymore.

In a recent column, I looked at the differences between Apple Computers rollout of Mac OS X and Redmonds plan for Vista. The pricing strategy behind OS X was vastly different than Windows, but even more striking was the concept behind the move.

To ensure that customers workflows would be maintained and to ease their minds over the transition, Apple shipped the new OS X along with the older Mac OS 9. It was up to users to decide whether their workflows could go forward in OS X and its emulation environment for older software. If not, customers could boot into Mac OS 9. This choice was offered for more than a year and a half following the initial release of OS X v1.0.

/zimages/2/28571.gifRead here about how Vistas release in Europe will be delayed.

While most readers responded that they would take their time in moving to Vista—a good many of them offering some form of "forget about it"—others said we should all just get with the plan.

"Vista has a compatibility mode for old apps (as did XP, but Vistas is better)," reader Patrick Chefalo said. "If you have problems running an application in the beta, Vista notices and asks you if youd like to re-run it in compatibility mode. If it works, it asks you to add it to a list of apps permanently in compatibility mode. The list is available for inspection."

In addition, Chefalo pointed to the bundling of the forthcoming Virtual PC 2007 with Vista Ultimate as an assist for transition. "Microsoft offers Virtual PC for free now. You can host (if you have sufficient RAM and processor resources) a guest OS, such as 2000 or 98, on a Vista or XP box," he said.

This virtualization approach is a hot topic in the Vista community. For example, in a recent post, Vista tester Brandon LeBlanc talked about dual-booting in Windows and of running Virtual PC 2004 with the latest beta.

Of course, the performance of these compatibility layers and virtualization solutions in actual workflows remains to be seen. As we discovered with the transition to Windows XP SP2, the real world can interfere with the hype. Theres a world of difference (and just two letters) between "if it works," as Chefalo said, and "it works."

/zimages/2/28571.gifAccording to eWEEK Labs review of Vista RC1, the migration path to Microsofts next-gen OS may be a rough ride. Click here to read more.

Where is Microsofts list of compatible and incompatible applications as it provided for Windows XP SP2? Certainly, with driver incompatibilities, a rewritten security stack and new user interface, Vista will require software developers to update many programs. Customers need to know what is working now in order to budget for a transition and perhaps to put some pressure on ISVs and consultants for a timeline.

Both Microsoft and Apple could take a lesson from IBM on the subject of OS transitions and compatibility, according to M. Carl Gehr, mainframe systems analyst and developer with the Edge Information Group of Cincinnati.

"In general, user software (versus system-support software) written for the original IBM OS/360 back in 1965-66 will likely run with no changes at all on the latest z/OS operating system and the latest System z hardware being delivered today," he wrote in response to the column.

/zimages/2/28571.gifIBM recently started an academic initiative to boost the place of its z/OS in the college curricula. Click here to read more.

Even more significant, Gehr continued, is that IBM delivered downward compatibility for applications running in the LE (Language Environment) run-time support.

"That is, you can develop and test an application in the latest level of LE and as long as you do not use features of the hardware or operating system that were not available on the old levels, that code will run just fine on the old hardware and software," he said.

This compatibility goes back to 1998 levels and even before, Gehr noted. "Now, this is the right way to deliver upgrades," he concluded.

Next Page: A better way for downward compatibility.