Microsoft takes great pains to ensure that each new version of Windows remains backward compatible with older applications. But if Internet Explorer is any indication, writing a modern application for Windows 8 that still runs on older platforms is a lot harder than it sounds.
Each preview release of Windows 8 shipped with two builds of Internet Explorer 10 – one for the desktop and one for the new, touch-centric Start Screen – and early-access users of the Release to Manufacture (RTM) version of Windows 8 have had the final IE10 code since August.
When users of earlier versions of Windows will get their hands on Redmond's latest browser, on the other hand, remains unclear.
According to a blog post issued on Wednesday, Windows 7 users will be able to download a version of IE10 in mid-November, but it will only be a preview release, and Microsoft still has not committed to any timeline for when a production-ready version will become available.
This won't be the first time Windows 7 users have been given a sneak peek at the new browser, either. Microsoft last offered a preview version of IE10 for the older OS in June 2011. At the time, it described the early build as a "platform preview" aimed at getting web developers accustomed to the latest HTML5 technologies.
But maintaining that momentum wasn't much of a priority, it seems, because there's been nary a peep from the IE group about anything but Windows 8 since then. Even the latest announcement commits to nothing, other than that "final availability [will] follow as we collect developer and customer feedback."
Here at El Reg's California aerie, this strikes us as a little odd. It would be one thing if Microsoft wouldn't commit to offering IE10 on Windows XP; that OS is nearing the end of its support lifecycle anyway. But by most accounts, Windows 8's desktop mode is almost 100 per cent compatible with applications built for Windows 7. What's so special about IE10 that it can't be made to work with the older OS, now that the final code is in the can?
Meanwhile, Google, Mozilla, and other IE competitors are hard at work building new versions of their browsers that integrate with Windows 8's new features while still remaining compatible with Windows 7 and earlier. If Microsoft doesn't plan to offer a production-ready version of IE10 for older operating systems until months after Windows 8 ships, some customers will inevitably jump ship.
Redmond says it will offer its latest browser for older versions of Windows in due time. For now, however, it seems the only way Microsoft will supply you with a modern browser that complies with the latest open web standards is if you agree to upgrade to its newest proprietary OS. There's a certain irony in that. ®