Not sure if this has been posted but the old window manager CDE has been release as open source.
Anyone who has been on unix/qnx/solaris/aix or other commercial type systems might have remembered it or still use it today (as I do).
I remember the day when Metro was the only game in town. It cost more than the OS as I recall.
Hope to get it running on a system soon.
Their site is borked a bit but you can get to sourceforge and get the alpha file.
www.cdesktopenv.org/
If all this has been posted then a mod is welcome to delete this post.