iPod (2001 to present)
Platform size: 20
As a consumer electronics gadget with a streamlined interface and (very) limited third-party software support, the classic iPod series is something that few people think of as a computer platform. But underneath those fancy click wheels lay the beating heart of a computing machine.
Every member of the classic iPod family (save one, the first iPod Shuffle) has sported an ARM-based CPU, most in configurations designed by PortalPlayer. Similarly, almost all classic iPods run a custom version of the Pixo OS, an embedded operating system initially licensed by Apple (and later bought outright from the Pixo company itself).