Distributions for the Raspberry Pi at a glance

No other computer switches its operating system as easily as the Raspberry Pi: Just slot in an SD card with a different OS image, reboot, and you're done. But, which of the available Rasp Pi operating systems is best for you?

Most of the systems that run on Raspberry Pi are versions of the Linux operating system. Because Linux is open source, developers can tailor it for specific purposes. In the case of the Raspberry Pi, the light hardware requires a scaled-down system free of unnecessary applications and the "code bloat" common on many desktop systems. Also, systems that run on Raspberry Pi must be compiled for the Rasp Pi's ARM processor – an ISO image created for a desktop computer with an Intel processor won't work.

This article introduces some of the operating systems designed to run on the Raspberry Pi [1]. As you will learn, many of these systems are ported from popular mainstream Linux distributions. Often the choice of a system is a matter of taste, but you might find that some systems work better for the way you intend to use your Raspberry Pi.

If you want to experiment, you can just burn different systems to different SD cards and trade them out whenever you want a new look. Or, you can try a system like NOOBS or BerryBoot, which offers up a convenient menu for choosing an operating system at boot time (see the "NOOBS and BerryBoot" box). You can even access an Amiga-like operating system (see the box titled "AROS – A Special Case").

Figure 1: AROS brings that Amiga feeling to the Raspberry Pi.

Considerations

If the operating systems described in this article weren't slightly different, they wouldn't all need to exist. Raspberry Pi users often develop a favorite distribution based on considerations such as:

• Package Manager – In the Linux world, users connect to package repositories to download new applications. The concept of a package repository was later adapted by Apple for the iPhone App Store, but in Linux, almost all of the applications are free. Several package formats and package management tools coexist in the Linux space, and users often form preferences about Linux distributions based on the repositories and package tools. The leading package tools are based around Debian repositories (with tools like Apt-get and Aptitude) and the Red Hat Fedora repositories (with tools like Yum). The Raspbian distro uses a Debian-based package environment, and Pidora uses RPM-based Red Hat packages. Some other distros, such as Arch Linux, maintain their own package management systems.
• Desktop – The desktop environment, with its distinctive screen layout, menus, and desktop applications, is another distinguishing feature of Linux systems. Popular desktops like Gnome and KDE are too bulky for the Raspberry Pi, which runs better with lightweight systems like LXDE and Xfce. Some Rasp Pi systems dispense with the graphic desktop altogether and boot directly to the old-fashioned command line.
• Multimedia – Some systems are optimized for audio and video playback. As you'll learn in this article, a number of Rasp Pi alternatives are intended to outfit the Pi as a media center. As is often the case with specialization, these systems are quite convenient for their intended use case, but they give up some flexibility if you want to use your Pi for other things.

Beyond these differences, you will find that the systems offer many of the same applications – either preinstalled or at least available for download. Most systems will support the projects described in this issue, although you might have to adapt some of the setup procedures. They all look quite similar once you get to a terminal window.

Raspbian

The most popular OS for the Rasp Pi is certainly Raspbian [6], a custom version of Debian GNU/Linux specially tailored for the mini-computer. Debian is widely used in server systems, and it forms the basis for several popular desktop distributions, such as Ubuntu. Thanks to the 35,000 packages in the Debian repositories, the user can draw on a huge amount of free software.

Raspbian is available in two variants: hard float and soft float. The difference between these variants has to do with how the system handles floating point numbers. The hard float form is much faster, so you will likely prefer it in almost all cases. However, if you want to use the Java VM from Oracle, you must use the soft float image. If you program in Java, or if you plan to run applications written in Java, you might want to consider the soft float edition.

After booting, Raspbian automatically starts the raspi-config tool that lets you customize key settings, such as the password and time zone in a small menu. Here, you can also select whether to boot to the lean LXDE graphical desktop (Figure 2) at boot time. The user interface and the Start menu of the graphic desktop help newcomers quickly find important programs: Thanks to the nimble WebKit engine, the Midori browser lets you surf the web at fast speeds; the visual development environment Scratch is also preinstalled.

Figure 2: The most widespread Rasp Pi distribution: The Debian GNU/Linux descendent, Raspbian.

If you also want to use your Rasp Pi for office work, you can use the package manager to install LibreOffice conveniently off the web. Despite its richness of features, the free office suite reacts surprisingly quickly. You'll see no performance issues with ordinary tasks, at least on the B model with 512MB of RAM. Understandably, however, huge tables with extensive computations take the Pi to its limits.

Raspbian is rightly considered the standard distribution for the Rasp Pi. On one hand, it facilitates a newcomer's first steps with the mini-computer, which is why it also forms the basis of many tutorials. On the other hand, advanced users who have used Debian or one of its derivatives already feel comfortable with it.