About 200 people attended the UKUUG Conference [1] at Bristol University coming from across the UK, Europe and around the world. The conference was held over 3 days, with 35 talks in total. An initial day of tutorials was also available for an additional fee. These were given by Ulrich Drepper [2], the glibc maintainer, and Jim McQuillan, founder of the Linux Terminal Server Project [3].

The first day featured talks on RAS (Reliability, Availability and Serviceability) by Richard Moore of IBM, the Exim Mailer, by its author Philip Hazel and GNOME 2.0 by Michael Meeks of Ximian. There was also a presentation on the port of the Linux Kernel to AMD's 64-bit 'Hammer' chip and two talks about running non-native applications on GNU/Linux systems using Dynamic Binary Translation and the Linux-ABI module. The day was rounded off with a talk entitled ``Buried alive in patches -- six months picking up the pieces of the Linux 2.5 kernel'' by Dave Jones of the 'dj' series of kernel patches, covering the hectic life of a kernel maintainer. Dave talked about the large amount of work that goes on, often behind the scenes, in order to get patches included into the mainstream kernel, and how some patches fail to get included for various reasons. This was followed by a panel discussion on the future of the Linux kernel led by Marcello Tosatti (2.4 maintainer). The discussions again centred the process of getting patches included in the kernel, and what features were likely to be included or excluded and when.

Saturday was the main day of the conference, and the programme was split into parallel sessions on this day in order to accommodate all the presentations. I attended a talk by Sander Striker one of the developers of the new revision control system Subversion [4], a next-generation version of CVS. Subversion was started by the CVS developers Jim Blandy and Karl Fogel of Cyclic Software, and is based on the Apache Portable Runtime library, making it guaranteed to run on any platform that Apache supports. Sander stressed that the Subversion project is leveraging existing free software as much as possible. For example, by using Apache to handle the networking they automatically get support for authentication, compression and encrypted sessions. Subversion also uses the WebDAV protocol from Apache's mod_dav module and so is compatible with any WebDAV enabled client. Its backend is based on Berkeley DB.

The afternoon began with a presentation about GNU/Linux on the Sony Playstation 2, by Sarah Ewen of Sony [5]. Sony is selling a developers kit which allows the Playstation to run a full GNU/Linux system. The kit includes a hard-drive, keyboard, mouse and network card. Although the development tools provided with the kit (such as GCC) are free software, Sony's runtime environment is not under a free software license. The runtime library is needed to access the Playstation hardware, and the version distributed with the kit is restricted to non-commercial use. A free software replacement for this library would be needed in order to write and distribute games under the GNU General Public License.

The main talk of the afternoon was a presentation on the GNU Hurd [6] by Marcus Brinkmann, one of the developers. The GNU Hurd is the GNU project's replacement for the Unix kernel. In comparison with existing "monolithic" kernel designs such as Linux or BSD, the GNU Hurd uses a new approach based on modular server components running on top of a microkernel. These servers work together to implement file systems, network protocols, and access control, by communicating through well-defined message-passing protocols. The use of independent servers for each task offers much greater security and compartmentalisation of errors than in traditional kernels. A bug anywhere in a monolithic kernel usually leads to a fatal error or "kernel panic" which freezes the entire system, but with the Hurd's modular design an error in one component is always isolated. Marcus commented that the Hurd developers make use of this when working on the servers -- when they hit a fatal bug in the code they can simply restart the affected process, rather than rebooting the entire system.

Marcus made clear that it would be a mistake to view the GNU Hurd purely in terms of its technical advantages -- on a higher level its design follows the GNU Project's goal of giving users freedom. In particular the modularity allows a decentralised development model for the kernel itself, since servers can be developed and installed independently. It is even possible for each user on a multi-user system to run their own servers, without affecting other users. Marcus pointed out that the controversial problems debated in the panel discussion on the Linux kernel the previous day could be seen as a consequence of the monolithic kernel model, which forces decisions about what should be included in the kernel. With a modular design such as used in GNU Hurd this problem does not exist, since the user has the freedom to mix-and-match components.

Although the Hurd is still in alpha release it is a stable and fully working system -- as was demonstrated by Marcus who began his talk by booting his laptop in to Debian GNU/Hurd, starting X Windows and giving a 1 hour presentation using the free software presentation program Magicpoint. Marcus encouraged anyone interested to visit the GNU Hurd web pages to look at projects needing work.

The final day of the conference began with a talk on the latest release of the GNU C library by Ulrich Drepper. This features a number of improvements to locale, thread and symbol versioning, and a new malloc which reduces the total memory usage of large applications such as Mozilla. The improvements to symbol versioning mean that in future it should be possible to prevent applications from being written which break when the C library is upgraded, since internal functions will be completely hidden from the user.

A later talk on web services was given by David Sugar of the Free Software Foundation's DotGNU Steering Committee. DotGNU [7] is the GNU Project's alternative to Microsoft's Dot Net and Passport. He first described the fatal weakness in Microsoft's proposal for web services -- it requires every user's personal data and credit card numbers to be stored in a central database, and this is a target for criminals, as well as being a single point of failure. In contrast DotGNU emphasises decentralisation and privacy. So, for example, in the DotGNU architecture any company can run its own external "profile server" allowing employees to seamlessly log-on to internet sites from a single sign-on within the organisation. The DotGNU protocols ensure that any information given out is always under the control of the user. According to David there is the potential for significant commercial interest in a vendor-neutral webservices framework using free software, such as DotGNU, particularly in areas where privacy is at a premium such as banking.

The conference also featured an exhibitors area, with a number of commercial stands, plus a Debian GNU/Linux area, where Debian developers were helping people with internet access [8]. Also present was journalist Dave Green of NTK [9] (the ``Need to Know'' newsletter) selling t-shirts, with a portion of the proceeds supporting the Campaign for Digital Rights [10], and the Association for Free Software (AFFS) [11] distributing leaflets and membership forms.

The conference was well organised, with the delegates pack even including a CD-ROM of the conference proceedings and source code of related packages. Unfortunately the free LPI Exams did not go ahead, but an extra conference dinner on the Saturday evening was added to the programme.

Next year's conference will take place in Edinburgh.

Open to UKUUG Members (Membership 35 pounds + VAT per year)

Conference Fee 34 pounds + VAT
Tutorial 60 pounds + VAT

[1] UKUUG, The UK Unix User Group, http://www.ukuug.org/
[2] Ulrich Drepper, http://people.redhat.com/drepper/
[3] LTSP, http://www.ltsp.org/
[4] Subversion, http://subversion.tigris.org/
[5] GNU/Linux on Playstation 2, http://playstation2-linux.com/
[6] GNU Hurd, http://hurd.gnu.org/
[7] DotGNU, http://www.gnu.org/projects/dotgnu/
[8] Debian GNU/Linux, http://www.debian.org/
[9] NTK, http://www.ntk.net/
[10] Campaign for Digital Rights, http://uk.eurorights.org/
[11] Association for Free Software, http://www.affs.org.uk/