I think there were a couple reasons ARM won: * ARM wasn't directly in the manufacturing business. This meant they weren't a supply chokepoint when demand scal

I think there were a couple reasons ARM won: * ARM wasn't directly in the manufacturing business. This meant they weren't a supply chokepoint when demand scaled by a factor of thousands. Just take the IP core and fab it yourself! * They triangulated the market unexpectedly well. There was a definite gap in the market between "performance at any cost" big architectures (x86/Itanium/Power/PA-RISC/SPARC) and "Draws no current, but gets winded running the clock for a VCR" (6502/Z80/68HC11/Atmel/PIC) little ones. For a long time, this was filled by on an ad-hoc basis-- one-off designs for game consoles, set-top boxes, and ahead-of-their-time smart appliances. Most of these were closed, single-vendor, no-interoperability systems where "ease of integration" and "off the shelf tools" didn't really matter, so we had all sorts of bit players. It took the arrival of full-power handheld devices with third-party software support (PDAs and then smartphones) for a large demand to appear, and ARM was ready with a product line that fit the space well. Compare the alternative, a world where we had had x86-based Windows CE devices and eventually iPhones. Intel/AMD/VIA would have been scrambling to put together the diversity of custom designs these devices cried out for. It would have required a massive respin of their architectures (look how hard it was to get Atom into a phone-ready state, and even then it did poorly) and then backlogged their foundries.