>The company was founded in November 1990 as Advanced RISC Machines Ltd and structured as a joint venture between Acorn Computers, Apple Computer (now Apple Inc.) and VLSI Technology.

>The new company intended to further the development of the Acorn RISC Machine processor, which was originally used in the Acorn Archimedes and had been selected by Apple for its Newton project.

https://en.wikipedia.org/wiki/Arm_Holdings#Founding