AIM was an alliance formed between Apple Computer, IBM and Motorola to create a new computing standard based on the PowerPC architechture.
The goal was originally to produce both the CPU design and a common architechture based on it, called PReP (for PowerPC Reference Platform), and later CHRP (for Common Hardware Reference Platform). PReP was in fact a barely-modified version of IBM's existing RS/6000 platform, changed only to support the new bus style of the PowerPC (based on the Motorola 88000).
Efforts on the part of Motorola and IBM to popularize PReP/CHRP failed when Apple consistently (and deliberately) did not provide a version of the Mac OS that could run on it. Although the platform was eventually supported by several Unix flavours as well as Windows NT, these operating systems generally ran just as well on Intel-based hardware so there was little reason to use the PReP systems.
The PowerPC effort fared much better, but in 2000 IBM sold its remaining stake in their shared Somerset design center to Motorola, apparently losing interest in the PowerPC architecture. Recently IBM resumed development of the PowerPC line with a 64-bit microprocessor partly based on their own (largely compatible) POWER series.
