Arm Holdings plc is a semiconductor and software design company based in Cambridge, England, whose primary business is the design of central processing unit (CPU) cores that implement the ARM architecture family of instruction sets. It also designs other chips, provides software development tools under the DS-5, RealView and Keil brands, and provides systems and platforms, system-on-chip (SoC) infrastructure and software. As a holding company, it also holds shares of other companies.