RapidMind Software

Grew out of Sh meta-programming (Waterloo)
Not source compatible with Sh but very similar concepts.
High level, C++ very heavy use of templates
Compatible with free GNU C++
Templates/GDB on occasion produce huge incomprehensible error messages leading to a difficult learning path.
Very active, new releases, targeting new hardware. Suggests RapidMind will be a viable option in the future as well as now.
Still feels like beta release. 18 bugs/gotchas reported.
Active developer support
Integrated compiler for GPU works almost without problem.