Most microprocessors—the chips that do the grunt work in computers—are built around designs, known as instruction-set architectures (isas), which are owned either by Intel, an American giant, or by Arm, a Japanese one. Intel’s isas power desktop computers, servers and laptops. Arm’s power phones, watches and other mobile devices. Together, these two firms dominate the market. Almost every one of the 5.1bn mobile phones on the planet, for example, relies on an Arm-designed isa. The past year, however, has seen a boomlet in chips made using an isa called risc-v. If boomlet becomes boom, it may change the chip industry dramatically, to the detriment of Arm and Intel, because unlike the isas from those two firms, which are proprietary, risc-v is available to anyone, anywhere, and is free.