NVIDIA had been struggling with Linux 3.11/3.12 kernel support to the extent that AMD's Catalyst driver even worked earlier but the 331.20 Linux GPU driver released today has the workaround for supporting these recent kernel releases.
The NVIDIA 331.20 binary driver also updates the NVIDIA driver installer to now detect the EGL GLAMOR library (libglamoregl.so) X extension module as it conflicts with the NVIDIA binary driver. GLAMOR is just used by the AMD RadeonSI driver and other select use-cases for doing 2D acceleration over OpenGL, but conflicts with NVIDIA's libGL and libglx.so modules.
Besides the modern kernel support, the other interesting feature is NvFBCOpenGL. Many Linux desktop users know how desktop screen recording of OpenGL games or video playback can be a very choppy and sluggish experience, but now there's a new NVIDIA library.
The NVIDIA OpenGL-based Framebuffer Capture (NvFBCOpenGL) library is all about high performance and low-latency captures while also having support to encode the composited frame-buffer of an X11 output. Sadly, however, NvFBC and NvIFR are private APIs... While NVIDIA is nice sometimes like in the case of making the VDPAU video encode/decode API open to the community, NvFBCOpenGL is not. Anyone interested in the interfaces for using this new NVIDIA library must contact the company for details.
The NVIDIA 331.20 driver also has various bug-fixes and other changes carried over from the earlier NVIDIA 331.xx Linux driver betas, including initial EGL support for 32-bit Linux.
The NVIDIA 331.20 Linux driver can be downloaded at NVIDIA.com. The Solaris and FreeBSD drivers have been updated too.