On Thursday, in addition to releasing the new 8GB Raspberry Pi 4, the Raspberry Pi Foundation announced that it was changing the name of its official operating system from "Raspbian" to "Raspberry Pi OS." For Pi fans who've been using (and writing about) the operating system for years, this is a fairly consequential change, but not one without justification.
The organization that develops and sells Raspberry Pi hardware will now support two different types of its first-party operating system, the traditional 32-bit variety that was formerly known as Raspbian and a new, 64-bit one that looks the same but enables you to use 64-bit apps that can consume more than 4GB of RAM. Both platforms will be named Raspberry Pi OS, just as Microsoft, which has both 32 and 64-bit OSes, calls both of its products Windows 10.
So why not just name the 64-bit operating system Raspbian (64-bit)? The answer lies in the history of Raspbian and the people behind it. First developed in 2012, the year that the original Raspberry Pi launched, Raspbian is a 32-bit fork of Debian Linux that's optimized for the Pi, especially the BCM2835 ARMv6 processor that powers the Raspberry 1 and Raspberry Pi Zero.
Raspbian is run as its own open-source project by developers Peter Green and Mike Thompson and, though they work closely with and are supported by the Raspberry Pi Foundation, they are an independent entity. However, the first-party "Raspbian" OS image that users have been downloading from the Raspberry Pi Foundation is just one image of several that are built on the Raspbian core. Raspbian.org lists several other Raspbian-powered OS images compiled by other organizations, though most haven't been updated in years.
The new, 64-bit operating system doesn't use software from the Raspbian project at all, instead taking its "userland," the part of the OS that floats above the Kernel, from Debian arm64. In a post on the raspberrypi.org forums, Green explains that he doesn't want the Raspbian name used for something that doesn't incorporate code from his project.
"For a while now raspberry pi have been considering 64-bit images," Green wrote. "Eben [Upton, founder of Raspberry Pi] sent me an email asking my opinion about nomenclature and I expressed that I would not be pleased about the use of the name "Raspbian" for images that did not contain anything from Raspbian."
Green also wrote that he plans to continue the Raspbian project, which will undoubtedly continue to be used to build the 32-bit version of Raspberry Pi OS. Considering that many models of Raspberry Pi, including the very-popular Raspberry Pi Zero, will never work with a 64-bit OS, the 32-bit platform will continue to be important if not dominant for years to come.
According to Raspberry Pi Founder Eben Upton, the name change to Raspberry Pi OS makes sense, because Raspbian has always been the underlying technology, not the platform itself. In a statement to Tom's Hardware, he wrote:
"Raspbian is an independent open-source project, which maintains a rebuild of the Debian armhf port modified to run on armv6 hardware. Starting from an armhf bootstrap, NEON fastpaths and a small number of armv7-only scalar instructions are removed through build settings). Using Raspbian allows us to take advantage of the hardware floating point unit on the original BCM2835 AP, which using the "official" Debian armel port wouldn't.
So when we say 'Raspbian image' what we mean is 'our Raspberry Pi operating system image built using the Raspbian repos', but what people hear is 'Raspbian is the name of Raspberry Pi's operating system.'
This confusion is fairly harmless, until you get to 64-bit. The 64-bit equivalent of 'Raspbian' is 'the Debian arm64 port.' It isn't 'Raspbian' or 'Raspbian64' or anything like that. So we're overdue for an actual name for the OS, and we're taking the opportunity to clear up the confusion around the 32-bit OS at the same time."
The first release to be labeled Raspberry Pi OS launched on May 28th, with several new features, including Bookshelf, an app that offers free issues of MagPi, the official Raspberry Pi magazine. You can see the new name in the splash screen at bootup, but you'll still find the Raspbian nomenclature in some parts of the OS, including when you use the cat /etc/os-release command.