I am looking for an open source software implementation for OpenCL. I know Mesa clover is one. But its development has been slow and incomplete so far. Any information on similar software is welcome.
I know you mentioned explicitly “open source”, but you may be interested in AMD’s x86 implementation anyhow since there are binaries available for Linux. http://developer.amd.com/gpu/ATIStreamSDK/Pages/default.aspx
…and it’s free as in beer.