The BeagleBone Black uses a AM335x 1GHz ARM Cortex-A8 processor from Texas Instruments. It comes with a 3D graphics accelerator, ARM Cortex-M3 for power management, and 2xPRU 32-bit RISC CPUs. You can additional details and hardware specs of the BeagleBone Black here.
Software compatibility includes Angstrom Linux, Android, Ubuntu, and Cloud9 IDE on Node.js with BoneScript library, among others.
[Image courtesy: BeagleBoard]