Pitoiset has been for months working on various compute shader work for the Nouveau open-source NVIDIA driver stack as well as the Gallium3D code at large.
A few months back he landed Nouveau compute support for Fermi, a.k.a. the NVIDIA GeForce GTX 400 / 500 series. Kepler support wasn't ready at the time due to issues, but now it appears to be set.
Samuel published a patch series today for handling compute shaders for Kepler GK104 hardware within the NVC0 Gallium3D driver. With these 11 patches that amount to around 500 lines of reworked code, the OpenGL ARB_compute_shader extension can now work on the GK104 while GK110+ GPUs still need some extra work.