Pixo

Pixo is the operating system used by all early iPod models until the introduction of iPhone OS (later iOS) in the iPod touch.

History
The Pixo OS was originally created by Pixo, Inc., founded in 1994 by Apple Computer veteran Paul Mercer. The company began licensing the source code to its operating system in May 2001. After the Pixo OS was developed and delivered to Apple under contract, Pixo, Inc. was eventually sold to in 2003.

Pixo was introduced in the first iPod in November 2001 as a simple monochromatic list-based interface. Color was introduced in 2004 with the iPod photo. The Cover Flow interface from iTunes was introduced in 2007 with the 3rd-generation iPod nano and 6th-generation iPod (thereafter known as iPod classic). The 6th-generation iPod nano introduced a Multi-touch version of Pixo that resembled iOS. As the iOS-based iPod touch became the best-selling iPod model, sales of versions that used Pixo diminished. Sales of the last remaining Pixo-based models, the 4th-generation iPod shuffle and 7th-generation iPod nano were discontinued on July 27, 2017.