Acorn Computers created the ARM architecture before the technology was spun out into a separate company in 1990.
Acorn developed the architecture for the ARM1 processor in the 1980s while designing computers for the British market. ARM originally stood for Acorn RISC Machine, with RISC meaning reduced instruction set computer. The approach emphasized a relatively small and efficient instruction set.
In 1990, Apple, Acorn, and VLSI Technology helped establish Advanced RISC Machines, later known simply as Arm. Arm generally licenses processor designs and instruction-set technology rather than manufacturing chips itself. This model allowed its designs to appear in products made by many other companies.
Arm-based processors became especially widespread in mobile phones because of their power efficiency. The company’s public listing and high valuation reflect the importance of licensing intellectual property throughout the semiconductor industry. Acorn, the original creator, is often omitted from simplified histories of Arm.