Source: news.com [news.com.com]

Currently, Linux users can play Windows Media Video (WMV) and Windows Media Audio (WMA) content if they install closed-source modules (...) That will change as the result of a licensing deal RealNetworks has signed with Microsoft and its settlement of an antitrust suit against the software giant. It will release open-source code to play the files as part of the Helix Community project it launched to bring RealNetworks technology to Linux.