Arm Ltd.

Arm Limited (stylized as arm) is a  and  design company based in,. Its primary business is in the design of processors (CPUs), although it also designs other chips;  under the DS-5, RealView and  brands; and, system-on-a-chip (SoC) infrastructure and software. As a "holding" company, it also holds shares of other companies. It is considered to be for processors in s (s or otherwise), s and for chips  in s and in total over 160 billion chips have been made for various devices based on designs from Arm (more than from any other company). The company is one of the best-known "" companies.

History
ARM was originally an acronym for Acorn RISC Machine, now Advanced RISC Machine. While ARM CPUs first appeared in the in 1987, a, today's systems include mostly s, including all types of s. Systems, like  and Android smartphones, frequently include many chips, from many different providers, that include one or more licensed Arm cores, in addition to those in the main Arm-based processor. Arm's core designs are also used in chips that support all the most common network-related technologies.

Processors based on designs licensed from Arm, or designed by licensees of one of the, are used in all classes of computing devices (including in space). Examples of use of those processors range from, to s, laptops, , servers and to  included on the  list (and including at one point, in 2019, the most energy-efficient one on the list). Processors designed by Arm or by Arm licensees are used as s in s, including safety systems. Arm's of graphics processing units (GPU) is the third most popular GPU in mobile devices. A recent addition to their lineup are chips for  processing.

Market competition
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 American and Japanese technology companies,  , and increasingly  and Intel. Despite competing within GPUs, Qualcomm and Nvidia have combined their GPUs with Arm-licensed CPUs.

Ownership
Arm had a primary listing on the and was a constituent of the. It also had a secondary listing on. However Japanese telecommunications company 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.

On 13 September 2020, it was announced that would buy Arm from SoftBank for $40 billion, subject to regulatory approval, with the latter acquiring a 10% share in Nvidia. In December 2021, the filed a lawsuit to block the deal, claiming that Nvidia's ownership of  could stifle innovation and competition in the processor market.

Microsoft and ARM
Microsoft announced in December 1996 that it was porting Windows CE to run on third party devices running processors, such as ARM and. In June 2012, Microsoft introduced its first ARM-based hardware with the Surface tablet, which ran Windows RT, an ARM-native version of Windows 8. However, the ARM versions were slow to catch on, compared to the Intel-based options.

Windows versions developed for ARM
The following versions of Microsoft Windows support :
 * Windows CE
 * Windows Phone
 * Windows RT (8.0)
 * Windows 8.1
 * Windows 10
 * Windows 11

In June 2021, Microsoft introduced ARM64EC, an (ABI) to help developers transition apps from x64 (Intel) code over to ARM. However, this development path is only supported for Windows 11, which includes to allow both types of code to run. Microsoft and AMD are reportedly working on new ARM-based chipsets for future Surface laptops.