Are GLSL and OpenCL equally capable?
They both run on the same hardware, but I don't have enough (or really any) experience with OpenCL to say if it feels more or less powerful than GLSL.
Edit: It turns out that I have no OpenCL hardware support (mid 2011 MBA), so I guess the hardware isn't necessarily completely similar (i.e. it can support GLSL and not OpenCL)