Raspbian

Raspberry Pi OS was first developed by Mike Thompson and Peter Green as Raspbian, an independent and unofficial port of Debian to the Raspberry Pi. The first build was released on July 15, 2012. As the Raspberry Pi had no officially provided operating system at the time, the Raspberry Pi Foundation decided to build off of the work done by the Raspbian project and began producing and releasing their own version of the software. The Foundation's first release of Raspbian, which now referred both to the community project as well as the official operating system, was announced on September 10th, 2013.

On May 28th, 2020, the Raspberry Pi Foundation announced they were releasing a beta 64-bit version of their official operating system. However, the 64-bit version was not based on Raspbian, instead taking its userland from Debian directly. Since the Foundation did not want to use the name Raspbian to refer to software that was not based on the Raspbian project, the name of the officially provided operating system was changed to Raspberry Pi OS. This change was carried over to the 32-bit version as well, though it continued to be based on Raspbian. The 64-bit version of Raspberry Pi OS was officially released on February 2nd, 2022.

Raspberry Pi OS is highly optimized for the Raspberry Pi line of compact single-board computers with ARM CPUs. It runs on every Raspberry Pi except the Pico microcontroller. Raspberry Pi OS uses a modified LXDE as its desktop environment with the Openbox stacking window manager, along with a unique theme. The default distribution is shipped with a copy of the algebra program Wolfram Mathematica, VLC, and a lightweight version of the Chromium web browser.