An Early Look at Progeny Debian 2.0

Remember Progeny Debian? It was a Linux distribution that set out to cure the ails of Debian proper, such as its unattractive installation program, many tedious steps requiring detailed knowledge of one's hardware, the unintuitive interface of dselect, and other annoyances that were seen as major obstacles in the way of wider adoption of Debian (and Linux) among the computing public. When Progeny released version 1.0 in April 2001, many users were impressed: "I really want to point out that this distribution was very, very easy to install. My first installation just awed me..." wrote one reviewer.

The project was buried some 6 months later. Ian Murdock, the founder of Progeny (and Debian) explained:

The company itself survived by switching its focus to providing services and commercial support for the Debian distribution.

Then this week, all of a sudden, Progeny announced the release of Progeny Debian 2.0!

Why the sudden revival of the Progeny distribution, rejected 3 years ago as a liability? Of course, Linux has come a long way since 2001 when it was a lot harder to sell. More importantly though, Ian Murdock has been promoting a radical new idea, a so-called "Componentized Linux", as a novel way of developing a Linux distribution as a collection of components, rather than as a monolithic whole. Progeny Debian 2.0 is the first released based on the concepts of Componentized Linux.

Before we go any further, let's try to explain these concepts: what exactly is Componentized Linux and why is it better than the traditional development model? In doing so, we'll skip the definition on the Componentized Linux home page, which is too abstract to make an impact, and go straight to the directory listing the currently available components:

• audio
• cups-1.1
• evolution-1.4
• gnome-2.4
• graphics
• linux-2.4
• linux-2.6
• lsb-1.3
• lsb-2.0
• lsbdev-2.0
• mozilla-1.5
• mozilla-firefox-0.8
• openoffice.org-1.1
• python-2.3
• tcl
• xfree86-4.2
• xfree86-4.3
• xml

The components can be added to /etc/apt/sources.list like this:

    deb[-src] http://archive.progeny.com/progeny/linux cl [components]

Each component represents a collection of packages. We can see a number of base components, such a linux-2.6 or lsb-2.0, essential for a core Linux system, and also a number of specialized components, e.g. audio or graphics. The important point of this "componentization" is that all components are self-dependent, in other words, all dependencies must be satisfied within the component itself, or a component has to explicitly specify another component that it depends on (e.g. one cannot install the gnome-2.4 component without one of the xfree86-* components).

It should be noted that this componentized structure is completely transparent to the end user. Taking Progeny Debian 2.0 as an example, the user can simply apt-get install or apt-get remove any package without having to think about the components; in fact, there is no way to install or remove an entire component with one command. The "componentization" only affects developers, it affects the way package maintainers create binary packages. For example, let's take a complex package with many dependencies, such as GnuCash. In standard Debian, the GnuCash package merely specifies which other packages must be installed on a system prior to installing GnuCash. However, in Componentized Linux, the developer will have to create a "gnucash" component, with all the dependent packages either inside the component itself, or specified in another component (such as the gnome-2.4 component).

How will this makes things easier and better? The way Ian Murdock envisages the role of components is that package maintainers will be able to create logical entities for specific uses. As an example, if a group of developers in Japan decides to add Japanese language support to a distribution, all they need to do is to create a complete self-contained component providing all packages needed for the language support. The component would include an input server, fonts, dictionaries, spellchecking applications and other relevant packages. Although it is hard to quantify the benefits of such approach until we have more exposure to the technology, there is no denying that a componentized structure does sound more logical, not to mention portable, than the present system of thousands of individual interdependent packages found in Linux distributions.

If you are interested in trying out this approach, Progeny Debian 2.0 provides an early taste of things to come. It is an alpha release, so expect a few problems here and there, but the cl-workers mailing list is a good platform for discussions, both technical and philosophical. Besides seeing the "componentization" effort in practice, the release is an evidence that the developers have put a lot of effort into the Anaconda for Debian port - unlike Progeny's early ISO image from 2 months ago, it is now possible to install the distribution in text mode. Also of interest to some should be the Progeny-enhanced version of apt, with support for SSL/HTTPS, HTTP cookies, interactive authentication, and redirects.

Although at present only Debian-based components have been created, the developers are planning to build components based on Fedora Core in the near future.

Index entries for this article
GuestArticles	Bodnar, Ladislav

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