Arm Holdings plc (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a British 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-a-chip (SoC) infrastructure and software. As a "holding" company, it also holds shares of other companies. Since 2016, it has been owned by Japanese conglomerate SoftBank Group.
While ARM CPUs first appeared in the Acorn Archimedes, a desktop computer, today's systems include mostly embedded systems, including ARM CPUs used in virtually all modern smartphones. Processors based on designs licensed from Arm, or designed by licensees of one of the ARM instruction set architectures, are used in all classes of computing devices. Arm has two lines of graphics processing units (GPUs), Mali, and the newer Immortalis (which includes hardware-based ray-tracing).Arm's main CPU competitors in servers include IBM, Intel and AMD. Intel competed with ARM-based chips in mobile but Arm no longer has any competition in that space (however, vendors of actual ARM-based chips compete within that space). Arm's main GPU competitors include mobile GPUs from technology companies Imagination Technologies (PowerVR), Qualcomm (Adreno), and increasingly Nvidia, AMD, Samsung and Intel. While competing in GPUs, Qualcomm, Samsung and Nvidia all have combined their GPUs with Arm-licensed CPUs.
Arm had a primary listing on the London Stock Exchange (LSE) and was a constituent of the FTSE 100 Index. It also had a secondary listing of American depositary receipts on New York's Nasdaq. However Japanese multinational conglomerate SoftBank Group made an agreed offer for Arm on 18 July 2016, subject to approval by Arm's shareholders, valuing the company at £24.3 billion. The transaction was completed on 5 September 2016. A planned takeover deal by Nvidia, announced in 2020, collapsed in February 2022, with SoftBank subsequently deciding to pursue an initial public offering on the Nasdaq in 2023, valuing Arm at US$54.5 billion.