The rise of the ARM architecture has been a meteoric one and came as something of a shock to many of the mainstream players in the mobile industry. The concept for the ARM based SoC (System on Chip) is pretty simple: build a small, energy efficient device that is able to use memory and processor cycles as efficiently as possible.  This is what x86 CPU manufacturers are trying to do as well.  So why are there more manufacturers of ARM based SoCs than there are x86? Well, the problem here is one of licensing. You see, it is much easier and less expensive to license the ARM architecture than it is x86. Right now there are very few players that even have an x86 license. This limits the competition down quite a bit and also (unfortunately) slows progress. However, the fight between Intel and ARM is just heating up. And despite the small number of players in the x86 market, things are far from certain in this area as we enter into a new round of combat between RISC and CISC (Reduced Instruction Set Computing and Complete Instruction Set Computing).