It is true: Windows 7 will drive the single biggest renaissance in Windows application design since the debut of Windows 95 nearly 15 years ago. I came to this conclusion while perusing the updated Windows User Experience Interaction Guidelines recently released by Microsoft in anticipation of the Windows 7 launch. As I poured over the various examples of Jump List variations and animated Taskbar icon overlays, it struck me just how much the Windows UI has evolved with Windows 7. For the first time in recent memory, I am actually excited at the prospect of seeing how third-party developers exploit the myriad new conventions. It wasn't always this way. Windows Vista revamped the UI's look and feel, but the changes were mostly skin deep: new dialog layouts, some tweaked button/control designs and, of course, Aero glass. Windows XP was likewise a yawner when it came to UI innovation. There were some new wizards and an updated visual skin (which was somewhat accurately described as having been "drawn in crayon"), but nothing that changed how you interacted with applications at a fundamental level. Contrast these non-examples with Windows 7 and you begin to see why this Windows version may have the same kind of lasting impact that its long-ago progenitor enjoyed in 1995. Back then, the concept of a "push button application switcher" (the Taskbar) was entirely new, as were the equally innovative Start menu and notification tray. Application developers practically tripped over themselves to exploit these innovations and to take advantage of Windows 95's 32-bit execution model. I predict a similar flurry of activity around Windows 7, as developers retrofit their offerings to provide the expected level of UI "freshness". Of course, not all is sunshine and roses with Windows 7. There's a real chance that these new UI conventions will simply widen the chasm that separates XP users from the current state of the art. The thought that you might need to upgrade your applications in order to fully realise Windows 7's usability benefits might be enough to give IT shops pause. In fact, the new UI may ultimately prove to be a liability as recalcitrant organisations latch onto it as yet another excuse not to upgrade. The old "retraining" bugaboo still has legs, especially in a struggling economy. And there is the issue of quality control. Developers have spent years figuring out what does and does not work under the "classic" Windows UI. Now, as they're presented with a box full of new visual toys to play with, there is a genuine risk that overeager developers will misuse the new conventions and deliver real clunkers that tarnish the platform's reputation. To its credit, Microsoft goes to great lengths in the guidelines to highlight the proper use of Windows 7's new UI conventions, including providing copious right-way/wrong-way examples. The question is, will developers take heed? As well, will the forces of intractability seize upon these and similarly nebulous objections as a way to once again postpone their migrations away from Windows XP? Time will tell, but I'm cautiously optimistic that Windows 7 will be a success and that we will see some real innovation with applications targeted at its unique UI conventions. In the meantime, developers would do well to peruse the aforementioned guidelines and avoid the kind of functional and visual blunders that have plagued so many of their predecessors. After all, you only get one chance to make a first impression.