Microsoft is planning to allow applications licensed under Open Source Iniative (OSI) approved licenses to be distributed via the Windows 8 app store.
That tidbit comes from a December 7 post on "The H" (which I saw via PCWorld). The H combed through a pre-release version of Microsoft's Windows Store App Developer Agreement and found mention of how open-source apps will be grandfathered in.
The H explained:
"Apps that are released under an Open Source Initiative-recognised open source licence can, at least in the pre-release version of the Windows Store, be distributed according to terms that contradict Microsoft's Standard Application License Terms if this is required by the open source licence. Among other things, the Standard Application License Terms prohibit the sharing of applications."
This loophole may help open-source developers avoid the kinds of issues encountered by some who were stymied Apple's more restrictive iOS App Store terms and conditions.
Microsoft officials shared more details about the coming Windows Store earlier this week. Metro-style applications will be licensable, marketable and downloadable from the Windows 8 Store. Non-Metro-style Desktop Apps will only be marketable from inside the store, with links provided to developers' sites for sales/downloads.
If you need a refresher as to what a "Metro-style" app is, here's my post from the Build conference about Metro earlier this year. And here's an updated architectural diagram, courtesy of Microsoft Most Valuable Professional Rockford Lhotka, with more detail as to what Metro vs. Desktop Apps on x86/x64-based Windows 8 looks like.