Microsoft will ship Internet Explorer 11 (IE11) with Windows 8.1 later this year, but on Monday the company passed on saying whether the same browser would also be available to Windows 7 users.
"We aren't sharing anything around which versions of Windows IE11 will be available on at this time," a spokeswoman said in a Monday email reply to questions about the new browser's OS destinations.
Microsoft has said little about IE11 -- it confirmed the browser only last week -- other than that it will be part of Windows 8.1, the free update to Windows 8 slated to launch as a preview June 26 and appear in final form some time this year.
"[IE11] is the only browser that is built for touch," Microsoft said in a May 30 blog post. "IE11 will offer even better touch performance, faster page load times and several other new features we think you will enjoy."
Microsoft has never limited a browser to a single version of Windows: From IE2 through IE5, in fact, its browser was multi-platform, supporting Macs until the company pulled the plug in 2003 after making good on a deal with Apple to provide a browser for five years.
Even IE10, which landed on Windows 7 about four months after it debuted on Windows 8, was always touted as a browser for both versions.
The mention of "built for touch" in the brief public description, however, may be a strong signal that IE11 will break with tradition and work only on Windows 8. While Microsoft baked some multi-touch technology into Windows 7, it paled in comparison to Windows 8, the OS the company continues to define as "touch first."
But IE10 on Windows 8 also handled touch, and Microsoft did build the browser for Windows 7, making it more like the Windows 8 version that ran in the latter's "classic" desktop. IE11 for Windows 7 could follow the same path.
There's precedent for IE11 to drop support for Windows 7: The last two Microsoft browsers -- IE9 and IE10 -- each ditched an operating system from its system requirements. IE9, which launched in 2009, supported only Vista and Windows 7, ignoring the even-then-aged Windows XP. Meanwhile, 2011's IE10 dumped Vista from the list, running on just Windows 7 and Windows 8.
The appearance of IE11 in Windows 8.1 also puts Microsoft on track for an annual update of Internet Explorer, something some experts believed Microsoft intended to implement two years ago. While an annual pace would be considerably slower than rivals like Google's Chrome and Mozilla's Firefox, which update every six weeks or so, it would be Microsoft's fastest tempo ever.
Microsoft also declined to comment Monday on whether IE11 would be made available to Windows 8 users who, for whatever reason, decide not to update their PCs and tablets to Windows 8.1.
For a few months after IE11's official launch, Microsoft will have to support a record six browsers -- IE6 through IE11 -- with security fixes. IE6 won't retire until April 2014, at the same time as Windows XP is put out to pasture.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is email@example.com.