ATSHELL version 0.21 has been released (10/12/2005). This is a RUNWORKPLACE (OS/2 desktop) replacement, which allows an arbitrary program to be used as the 'desktop', including the Workplace Shell (PMSHELL), but also a web browser or some custom application. The desktop program can be stopped and restarted without rebooting the system. It is licensed under the GPL, with full source code available.
http://www.cs-club.org/~alex/programming/os2/
Source: OS/2 Warp News and Rumors