A lot of effort is done from the open source community to support the windows format, a good example is VLC.

The best solution for now is the one developed by flip4mac, that was acquired by Microsoft in 2006.

In short, just go to the Microsoft web site and download/install their Quicktime component.

From the flip4mac readme: "After installing Flip4Mac WMV you can play Windows Media files in QuickTime Player and view Windows Media content on the Internet using Safari and other web browsers."

If you need to do more professional works, like exporting your movies in windows format, they also have a pro solution. But except for that, nobody needs the pro version.

Please let us know how it goes in the talk page.