ReactOS is an open source operating-system project aimed at development of a quality operating system based on Windows NT architecture, and that is compatible with Win32 applications and NT (XP, 2003) drivers.
Press-release: http://www.reactos.org/en/news_page_40.html
Full changelog: http://www.reactos.org/wiki/index.php/ChangeLog-0.3.4
Download packages: http://sourceforge.net/project/showfiles.php?group_id=6553&package_id=6629&release_id=570498
ReactOS website: http://www.reactos.org