Article gives a good overview, but skips a few key points: 1) Open ISAs have been around for a long time, notably for academic purposes. Many of those are just

Article gives a good overview, but skips a few key points: 1) Open ISAs have been around for a long time, notably for academic purposes. Many of those are just... simple. But not good jack-of-all-trades. More recently, some existing ISAs with high-performance, commercial implementations were opened up (Sparc, Power). 2) A spiritual predecessor (MIPS) was fairly successful back in the day. And lives on in Loongson. 3) Gaining traction took several tries (see eg. OpenRISC). And the "V" has meaning. So what's different with RISC-V? a) It's actually very well-designed. Modular, with modern demands in mind but an otherwise 'boring' ISA cherry-picking the best features of successful, existing ISAs. And designed for practical applications & scale from microcontrollers to datacenters. b) Tools used for early designs (simulators, FPGA boards, prototype silicon tapeout etc) have become much more accessible to hobbyists, universities, small startups etc. So the bar to join in & create implementations was far lower than say, 1..2 decades earlier. c) Timing of its introduction was pretty good. Open source software became commonplace. Open hardware gaining ground. But a good, scaleable, open ISA was lacking. Article emphasizes the "open" aspect heavily. But imho the reason industry jumped on it, was RISC-V bringing above factors together. $0.02 royalties/chip doesn't count, design flexibility + rapidly growing & maturing ecosystem does.