Steam doesn't open!

Running Steam on ubuntu 15.10 32-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(0)
pci id for fd 7: 80ee:beef, driver (null)
libGL error: core dri or dri2 extension not found
libGL error: failed to load driver: vboxvideo
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast