The Ubuntu Linux distribution has attracted a broad audience of Linux enthusiasts, and it's beginning to gain traction among mainstream computer users. Although Ubuntu is relatively new, it builds on the rich history and deep roots of the venerable Debian project, one of the oldest and most influential Linux distributions. The fate of the two popular flavors of Linux is as inextricably bound as their respective histories.

Although Debian is an extremely important part of Ubuntu's past and future, many new Ubuntu users know little about Ubuntu's roots and the nature of the relationship between the two distributions. In response to the numerous e-mails that I've received from inquisitive readers who are new to Linux and Ubuntu, this overview offers my own perspective on the importance of Debian and the role that Ubuntu plays in the Debian ecosystem.

Welcome to history class.

Debian: a strong foundation, a few cracks



Debian, which was founded by Ian Murdock in 1993, offers several important advantages over competitors. It has an extremely powerful package management system and a rich selection of available software. Recent counts show that the latest stable version has over 20,000 packages in the main repository and the latest unstable development version has almost 30,000.

Another key factor that differentiates Debian from many other distributions is its strong philosophical commitment and community-oriented development model, which are codified in the Debian Social Contract and Debian Free Software Guidelines. Debian is vendor-neutral and has high standards for transparency and democratic oversight.

Although Debian offers valuable advantages, the distribution has serious weaknesses, especially on the desktop. Its lengthy development cycles—with releases every two or three years—make it a poor choice for users who want the latest software.

Debian is offered in three different flavors: stable, testing, and unstable. Stable is used widely on servers, but many desktop users favor the testing or unstable versions because those provide more current packages. Unfortunately, there is no guarantee that testing or unstable versions will be fully functional at any given time, and users must occasionally contend with serious unexpected breakage.

Debian's ideological underpinnings are also occasionally an impediment rather than an asset. The project's commitment to democracy and intentional lack of strong centralized leadership sometimes cripples the decision-making process and contributes to an overall lack of direction. Development efforts can be impaired or derailed by endless non-technical disputes over specific ideological issues.

In the past, some of the dysfunctional aspects of Debian's governance model have alienated participants and compelled high-level contributors to abandon the project. Other distributions aren't immune to problems of this nature, but the pervasiveness of strong ideological convictions within the Debian community make it especially vulnerable.

Ubuntu: building mountains by filling in the holes



The Ubuntu Linux distribution originally emerged in 2004 as a Debian derivative under the strong leadership of South African entrepreneur Mark Shuttleworth. The raison d'etre of the Ubuntu project, which is developed through a collaborative effort between Shuttleworth's company Canonical and volunteer community developers, is to deliver a modern Linux distribution that is truly competitive on the desktop and suitable for mainstream non-technical audiences.

Ubuntu places a strong emphasis on ease of use and adheres to a consistent time-based release cycle. A new version is released like clockwork every six months on a schedule that is predictable and predefined. This ensures that the project will never stagnate or leave users with outdated software. The schedule is structured so it closely follows that of the GNOME project, the desktop environment that makes up the core of the Ubuntu software experience. Ubuntu is typically released one month after a new version of GNOME.

Ubuntu's birth was not a one-time fork of Debian. The two distributions are still closely tied, and a significant portion of Ubuntu's packages still come directly from upstream Debian. During the earliest stage of every Ubuntu development cycle, new and updated packages are automatically imported into Ubuntu from Debian's unstable branch. The import process occurs in a steady stream until the import freeze date, which generally aligns with an Ubuntu alpha release. After the import freeze, the packages in Ubuntu are hardened and tested extensively to ensure a higher level of reliability and robustness before the final release.

Viewed through the lens of its association with Debian, Ubuntu can be thought of as a series of Debian unstable snapshots that have been polished for general use. On top of that Debian-derived foundation, the Ubuntu developers simplify installation and make the distribution easier to use on desktop computers.

Ubuntu has a user-friendly Live CD installer that provides a complete environment out of the box and doesn't require the user to select individual packages or make any other choices. Ubuntu also includes tools that make it easy to automatically install and configure proprietary hardware drivers, codecs, and other components that many users require. These additions make Ubuntu a fully-functional desktop platform right out of the box with very little need for additional tweaking or manual configuration in most environments.

Ubuntu is an improvement in many ways, but Debian still offers certain advantages. One of the downsides of Ubuntu's time-based release management strategy is that sometimes useful updated packages don't make the cut-off. The rolling update model of Debian unstable ensures that it always provides the latest packages, albeit without any stability guarantees. Another huge advantage of Debian is that it supports a multitude of architectures, whereas Ubuntu only officially supports standard desktop computers and ARM.

Friction



Ubuntu still depends heavily on upstream Debian in many ways, but the relationship between the two distributions hasn't always been positive. Ubuntu's early successes put some strain on its ties with Debian and led to accusations of parasitism and inadequate reciprocation. The Ubuntu community has taken important steps over the years to ease tensions and address the conflict.

When the controversy first began to emerge in 2005, Debian founder Ian Murdock commented that the mutual success of Debian and Ubuntu would depend on the ability to ensure ongoing compatibility and collaboration between the distributions.

"If Ubuntu is part of the Debian family, then we all win if Ubuntu is a success. However, we all win if and only if Ubuntu remains a good son. My concern is that it's already starting to show signs of becoming the wayward variety, flush with confidence from early successes and starting to wonder if it no longer needs its parent," he wrote. "If Debian is to benefit from Ubuntu, the lineage has to be preserved, and it has to be stronger than 'we started with your pile of packages'."

Shuttleworth shared this view to a great extent and emphatically agreed that collaboration was and is the only way forward.

"I'm of the opinion that Ubuntu could not exist without Debian. So it's absolutely my intention to see that Ubuntu is a constructive part of the broader Debian landscape," Shuttleworth wrote several years ago. "It's vital that Ubuntu help to sustain and grow Debian, because it's the breadth and strength of Debian which make up the 'shoulders of greatness' on which we in the Ubuntu community stand when we reach for the stars."

The two disagreed on several key technical issues, however, as illustrated by their different opinions about the way to address interoperability issues. Murdock took the lead role in the DCC Alliance, an organization that was founded jointly by Debian and several derivatives with the aim of establishing an interoperable LSB-compliant common core for Debian distributions. Murdock hoped that this would guarantee compatibility between all Debian-based distributions and prevent the imminent balkanization that he feared. This plan was misguided on several different levels and its technical failings finally led to its collapse. Shuttleworth correctly predicted many of those problems and participated on the fringe without committing to adhere to the DCC standards.

There have also been several initiatives in both communities to increase collaboration, but these haven't been particularly successful. On the Debian side, the Utnubu project ("Ubuntu" backwards) was established to help bring Ubuntu packages into Debian. On the Ubuntu side, the Debian Collaboration Team (DCT) had similar goals. Neither of these gained much momentum, but they demonstrate the willingness on both sides to make collaboration work better.

Building closer ties



What finally helped improve relations was a change in culture within the Ubuntu community. A higher emphasis was placed on contributing to Debian and some individual Ubuntu teams began working with upstream Debian developers on specific projects. Ubuntu developers actively encourage contributors to file bug reports upstream where applicable and to participate directly in Debian development. There is also increasingly healthy collaboration in certain areas, such as with Python packaging. A joint packaging effort between the two distros was also recently announced for the transition to Mono 2.0.

Canonical's broader upstream contributions are also helping to ease tension in some ways. The proprietary status of the Launchpad development platform that is used extensively by Ubuntu was one particularly thorny issue. This problem was addressed earlier this year when Shuttleworth revealed that the entire Launchpad stack will be open source within the next year.

Canonical is also working with other members of the upstream community on some specific usability enhancement projects, such as a new notification system.

Although Ubuntu and Debian have largely reconciled their differences, the relationship between the two distributions isn't perfect and both Canonical and the Ubuntu community likely still have some work to do before they can completely transcend the perception that Ubuntu isn't giving enough back.

Ubuntu was made possible by the powerful legacy of Debian, and it continues to rely on the strength of Debian's diverse community to fuel its own advancement. Ubuntu's popularity has helped to increase the visibility of Debian, and the Ubuntu developers have gradually been aiding Debian more directly through collaborative technical efforts. Understanding Debian and its goals, values, and strengths will help to illuminate where Ubuntu came from and where it is going.