Redmond is taking a page from the early days of Mac OS X with Windows 7. Similar to Classic—Mac OS X’s emulation-based support for Mac OS 9 (and earlier) apps—the newly confirmed “XP Mode” that will appear in Windows 7 will use a VM for backwards compatibility with a previous-generation OS.

Win7’s XP Mode uses VirtualPC to run some XP apps. In a blog post (via CNET), the Win7 team says, “All you need to do is to install suitable applications directly in Windows XP Mode which is a virtual Windows XP environment running under Windows Virtual PC. The applications will be published to the Windows 7 desktop and then you can run them directly from Windows 7.”