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Linux live and kicking - Part 2

Craig Paterson — 2004-09-24T09:44:02.000Z

Craig Paterson, PC Magazine, Friday 24 September 2004 at 09:44:02

We continue our look at live distributions of Linux that you can use to find out if open source is for you before taking the plunge

Knoppix 3.3

The best known (and perhaps most mature) of all live Linux distributions is Knoppix from Klaus Knopper.

Knoppix gained rapid attention when introduced because it actually worked. The theory of using read-only media and a Ramdisk to run Linux is easy enough to grasp, but Knoppix went a step further with powerful hardware detection and automatic configuration.

Knoppix stumbled on our test machine with the nForce motherboard chipset, but booted fine on other systems, dropping into the crisp Knoppix-themed KDE 3.1 desktop.

About 2GB of software is crammed into the 700MB Knoppix image, and decompressed on the fly as required. It's impressive and makes for a fully featured working environment. Everything from the boot loader to the desktop is cleanly presented.

The default desktop environment is KDE, and both KOffice and OpenOffice are included for office work, and Konqueror and Mozilla for web browsing. Other software ranges from the MySQL database platform, including server, and a digital planetarium.

Documentation for users and would-be customisers is strong, with a well developed user community. Knoppix's Debian roots show through with the omission of some packages considered 'non-free' by the Debian GNU/Linux project, but overall it's a coherent distribution. The hardware detection isn't head and shoulders above the alternatives, but anyone considering a live Linux setup should take Knoppix for test drive.

Gnoppix 0.6.0-rc2

Despite the similar names, Gnoppix and Knoppix aren't part of the same project, although they come from the same evolutionary tree. Like Knoppix, Gnoppix is based on the Woody build of Debian GNU/Linux, but instead of KDE uses Gnome (and only Gnome) as its desktop environment.

Booting into Gnoppix is fairly quick and the hardware detection does a fair but not impressive job; our display defaulted to only 1,024 by 768 and, although the Ethernet adaptor was ostensibly detected and configured correctly, Mozilla couldn't connect to the internet. The version under test is prerelease, but other distributions did a better job of setting up.

The Gnoppix desktop environment is Gnome 2.4. OpenOffice is the only office suite provided, with Evolution 1.4 as the default mail client and Mozilla as web browser. Utilities are provided for setting up a persistent home directory. In addition to the staple items there's a wide range of utility software from the Debian archives.

Gnoppix is a mixed bag. The features and included software are good, but the packaging is rough around the edges. Other live distributions are cleaner and provide more options for desktop environments, browsers and office suites. However, if you're a big fan of Gnome and aren't dependent on totally automatic configuration, Gnoppix may be for you.

Morphix 0.4.1

A Knoppix descendant, Morphix offers a smaller download and a modular selection of applications. Variants are offered featuring Gnome, KDE or a Light option. The big selling point of Morphix is the ease with which you can roll your own setup. The user community is active and, in addition to documentation on how to customise your setup, the Morphix site includes links to many different specialist builds.

The Light GUI variant boots the quickest, although its startup is still slow compared with a stripped-down hard disk installation. The interface is a clean desktop with a launcher bar across the bottom of the screen.

Morphix KDE ships KDE 3.1 as its desktop environment and the KOffice suite. Morphix Gnome, on the other hand, goes for Gnome and OpenOffice. Otherwise the setup on each is similar, although the desktops themselves are distinct.

For gamers, the Morphix Gamer setup offers a neat out-of-box solution, with the lightweight IceWM desktop handling X-Windows duty, and a slew of games installed a couple of clicks away in the menu.

The documentation for Morphix makes it clear that the whole project is a work in progress, and shouldn't be considered a finished product. It is, though, under active development and we found it was well enough advanced for the enthusiast crowd, and nearly ready for prime time.

MandrakeMove

Originally the Mandrake distribution was Red Hat Linux compiled with optimisations for newer processors. It's since grown into a separate product and is now much more than just a souped-up clone of Red Hat, with MandrakeMove as the live variant.

MandrakeMove is available directly from MandrakeSoft. While it can be downloaded for free, users are asked to join the Mandrake Club or to go on to purchase a boxed copy. The boxed edition of Move is bundled at different price points with USB keys of varying sizes.

MandrakeMove boots directly into KDE 3.1. On our test systems the display auto configuration left us with a disappointingly low refresh rate. In a fashion similar to Linspire Live, the MandrakeMove desktop and menus are organised neatly along functional lines, rather than as a jumble of programs familiar only to experienced users. The office functions sit on top of Open Office 1.1, and the browser of choice is Konqueror.

System configuration is based on Mandrake's own Drak tool, which has a clunky interface in places but isn't unfriendly.

Overall, MandrakeMove is a quality distribution. While the hardware configuration could be stronger, the desktop environment is slick and compares well with Linspire Live.

SuSE Live

The live version of SuSE is specifically intended as a demonstration version of its regular counterpart. Accordingly, no customisation is available, and there are other ups and downs to this approach for the casual user.

First, SuSE Live takes a long time to boot. On boot the standard SuSE installer - YaST (Yet another Setup Tool) - kicks off to detect and configure hardware. While YaST does a superb job of setting up hardware, it takes a long time to do it, and the system proper does not boot up until YaST has completed its process.

These steps in the boot process itself (such as generating an SSH host key set) would normally be one-time operations for a hard disk install, but with a read-only system these are of course every-time operations.

Once the system has booted, though, things take a distinct turn for the better. A clean and well presented KDE 3.1 desktop has icons on the desktop for KDE's Konqueror browser and the Open Office suite. A well laid out menu and quick launch buttons in the KDE taskbar round out the polished feel.

The time waiting for YaST to complete is worth it; on our test system the resolution had automatically been set to a useable 1,280 by 1,024 with a refresh rate of 100Hz, and the network interface was properly determined and configured with DHCP. Mozilla is installed as well as Konqueror for those who prefer a different web browser.

SuSE Live hits its target market very well. It's not for the tweaker, and it takes a long time to boot. But it is polished, does a great job of detecting hardware and bundles a sensible suite of applications.

Mepis Linux beta 2

Until now Mepis has been a relatively unknown brand in the Linux world. As with many other distributions the standard offering is for a hard-disk based install, and the live version is a sideline. As sidelines go, though, this one has some interesting features.

On boot Mepis offers a GRUB-based menu of choices. Power users will appreciate the choices on offer, with different screen resolutions and different kernel versions. Once you choose an option the system starts up almost like a normal Linux box.

There's no pretty logo screen with progress bar, instead you can see the auto-detection routines doing their thing and subsystems initialising. This isn't as clean as some competitors, such as Knoppix (and its derivatives) or SuSE, but it works and is fine given the beta status of the release.

On our testbed Mepis had no trouble booting into a 1,280 by 1,024 KDE 3.1 desktop running on top of a 2.6.4 kernel. Both KOffice and OpenOffice are installed, as are Konqueror and Mozilla for web browsing.

Several Mepis custom utilities are provided for system management, including a hard disk installer that proved to be quick and flawless, installing a multiple kernel setup in just a few minutes.

The boot messages, look of the interface and overall packaging of Mepis aren't (yet) on a par with the better established or bigger name live distributions. But the feature set is good, and the distribution is up to date. For power users Mepis is already a good place to start, and it's getting better quickly.

Linspire Live

Formerly known as Lindows - the name was recently changed to avoid trademark issues - Linspire is targeted at the novice Linux user. Its live version is marketed mostly as a demonstration edition, but contains most of the functionality of the regular Linspire.

Getting Linspire direct from the manufacturer costs $30 (£17), but it can be downloaded from P2P services such as Kazaa and Bitorrent for free. This is permitted by Linspire because it saves the company the cost of supporting arbitrary numbers of huge ISO image downloads.

Right from boot Linspire (still branded 'Lindows') presents a clean interface that won't scare a novice user with in-depth descriptions of the boot sequence. Boot time is reasonable and once complete the user is dumped into a KDE-based desktop.

Unlike most other distributions the underpinnings aren't displayed up front. From the desktop itself through to the menus and the Internet Suite, everything is neatly branded as Lindows, which gives the environment a coherent feel.

The browser and mail client are both from Mozilla, and the (not rebranded) office suite is OpenOffice. Additional software is sparse but reasonable, and adequate for an office desktop.

Linspire Live is a cleanly presented distribution that shouldn't scare users new to Linux. It's not the most flexible or the most comprehensive option, but it's simple to use and covers the basics well.

LNX-BBC 2.1

LNX-BBC is a svelte distribution, at 50MB for the ISO image. The idea is that it will fit on a business-card sized CD-R so it can be conveniently carried around in a wallet. It's a similar idea to the Sysadmin Survival CD that Red Hat used to provide as part of its boxed Linux product. And, in a novel twist, if you join the Free Software Foundation your membership card will be a bootable CD containing LNX-BBC.

The space constraint of a 50MB image means that LNX-BBC has fewer features than the larger distributions. It's not intended as a drop-in replacement for a regular desktop Linux install but as a rescue CD for booting and inspecting systems.

Even here, though, LNX-BBC is conservative; the hard drives will be mounted read-only and you have to mount them manually to read/write to perform modifications. It's possible to roll your own variant of LNX-BBC using the GAR packaging system.

The current version of LNX-BBC is a little behind the curve, having been released in May 2003. That's not to say that this isn't a useful distribution, though. Plenty of tools are included for inspection and recovery of misbehaving systems, and the network facilities include SSH and Bitorrent clients.

LNX-BBC doesn't compete with the heavyweight distributions, but nor is it intended to do so. As a system recovery CD that fits in your wallet it can be forgotten about until you need it, and then it'll be a blessing.

Feather Linux 0.4.0

Continuing the 'small is beautiful' theme, Feather Linux demands just under 64MB. While it can be run from a CD, Feather is intended to run directly from a USB key drive. Unlike its big brother, Knoppix, you can run Feather from a USB key that doesn't cost almost as much as your PC.

Two variants are available: the standard Feather Linux and the Feather Linux Console Edition. The standard Feather aims to provide a small but useable desktop environment, including a surprisingly elegant and full featured window manager.

Space constraints mean that no office suite is included, but Feather does include music playback, administrative and network tools as part of the distribution, and tools to download additional software on a per-session basis.

The Console Edition is targeted at system administrators and is smaller still, requiring almost exactly 50MB. Very much along the same lines as LNX-BBC, the toolset is shaped towards diagnosing and repairing faulty Linux systems.

For most users Feather will be a compromise too far in terms of functionality. But for on-the-run system administrators Feather offers a neat and compact graphical environment along with a useful amount of power.

Conclusion

If you're new to Linux and considering a live distribution as an introduction without commitment, a handful of options stand out. Unsurprisingly it's the bigger distributions that offer the fewest surprises: SuSE Live, MandrakeMove and Linspire Live offer the friendliest interfaces as well as a good mix of tools.

SuSE Live is the most impressive introduction, with only its slow boot time counting against it, but with excellent hardware detection and configuration, and a good desktop.
Linspire Live goes far enough in branding that, in keeping with its Lindows heritage, it almost doesn't seem like Linux.
Mepis is a promising distribution that doesn't quite yet match the established players for polish, but is advanced with its 2.6 kernel option.
Mandrake doesn't match the SuSE hardware detection, but does have a polished desktop and applications bundle, and the option of a persistent home directory.

For the Linux enthusiast experimenting with live distributions the choice is a little different.

The polish of SuSE Live won't compensate for its demonstration-focus and slow load time.
The cosseted environment of Lindows isn't always the most comfortable for the long-time Linux user.
MandrakeMove is the only big-name distribution that matches the polish of a solid desktop environment and application mix with the convenience of persistent home directory.

But for tinkerers there's a lot more fun to be had with the custom distributions.

Knoppix shows its form as the longest-standing live distribution with wide-ranging documentation and a comprehensive set of included packages, packed into the 700MB of an 80-minute CD-R.
Gnoppix isn't quite as comprehensive, but is the just the thing for big fans of Gnome (KDE is the prevalent default environment across live distributions).
And perhaps most interesting of all is Morphix, with its modular system for building customised distributions including only what you need, all on top of a customised Knoppix.

From little acorns ...

Guy Kewney — 2004-03-05T10:48:36.000Z

Guy Kewney, PC Magazine, Friday 5 March 2004 at 10:48:36

Microsoft ignores the needs of small companies at its peril, because one day some of them at least are going to grow up.

Apple Computer is a big company and, if you sold software on commission, you would be in a very good mood the day you signed up the chief buyer of Apple as a customer.

But think about Estrella Van Damm, a sole trader consultant in the tiny Spanish town of Orgiva, whose business struggles to run on an outdated Pentium II with a dodgy keyboard.

You wouldn't waste the cost of a stamp to send this business a brochure. Yet the two companies are, potentially, the same.

Look back a few years, and you'll find that Apple started out using the Intel 8080 processor. Or at least, that was the plan. But the founders of Apple had cashflow problems.

They couldn't afford the Intel chip, and Intel wasn't prepared to do a deal. So they used an alternative chip, based on the rival Motorola architecture.

So much for nostalgia - but there's an important lesson for Microsoft here. At the end of 2004, Windows NT4 dies, and we've just had Windows 98 taken off death row for a short time. Microsoft is becoming quite nannyish about people working with out-of-date systems.

"So why would Microsoft invest in supporting those people?" inquired a consultant when I raised this subject. And, he suggested, Microsoft should regard these customers as "natural customers for Linux".

This reaction was widespread. When I queried the wisdom of this approach, they seemed to think I was advocating that Microsoft provide service to old software users as a form of charity. Absolutely not! But Microsoft does have a real problem here: a huge installed base that it simply can't cast off.

Businesses that are refreshing their hardware this year will throw out Pentium III machines that smaller companies can use to run Windows 2000. But running Windows 2000 on 'inherited' software is becoming difficult.

And when it comes to taking over machines with Windows XP, Microsoft's hard line on registration and updating means that Van Damm Consulting really will have to use Linux.

More to the point, when this small company stops working out of the garage and starts buying a dozen machines and a proper server, it will be a Linux user.

And the next generation of super-corporations will employ Linux-trained, Linux-equipped executives who think Windows is strange. They'll have relationships with Linux developers, and find Microsoft licensing confusing.

Fortunately, Microsoft's own executives don't seem to be suffering from the same myopia as some of its consultants. Senior executives at Redmond see the solution as the development of a mini-footprint version of Windows, based on Windows Mobile.

Such a platform could fulfil the functions of Windows 3.1 and Windows 9x that second-generation owners of hand-me-down PCs use them for today, but would be inherently more stable.

Disadvantages? Well, the margin for Microsoft on a PC is already smaller than you might think. A small-footprint ARM-based PC, clocked at 200-400MHz, can't be sold for much less than a full-spec Pentium 4.

But there are savings, and the more savings there are, the more Microsoft's share has to be cut.

I think that the 'developing world PC' is a potential money-maker, and that Microsoft will start promoting it shortly. And once that bandwagon starts rolling, the kiss of death for Windows 98 will be final and swift.

Classic Microsoft-induced paranoia?

Tony Westbrook — 2002-09-20T15:48:40.000Z

Tony Westbrook, PC Magazine, Friday 20 September 2002 at 15:48:40

Will the Redmond giant's forthcoming Palladium operating system turn out to be the Big Brother some are expecting?

I think I must be getting a little bit paranoid. I've just had Internet Explorer close on me, first asking if I'd like to send Microsoft an error report.

I said no and wondered whether my three Explorer windows had been closed because at that particular time I had three websites open, each containing a highly critical report of a new Microsoft project called Palladium.

Palladium isn't, as I thought, the name of a large theatre just off Oxford Street given to producing large family-oriented spectaculars. Palladium was the name of the building housing a statue of Pallas Athene, erected to protect the ancient city of Troy.

Microsoft has taken this name to describe its next-generation operating system, an act that presumably makes the Redmond campus the new Troy. Classical scholars will recall that Troy's end came when it was besieged by the Greeks at the end of the Trojan War by the Trojan horse. The statue of Pallas Athene proved useless in defence.

Having learned a little more about the plans behind Palladium, I can only hope that a similar fate awaits Microsoft's proposed protective edifice. For Palladium is a deeply unhealthy vision of the connected, globalised, US-centric world operated by mega corporations.

It might only be a vision-vapourware, but it's one that describes a world where software and data held on your PC are rendered unreadable or can even be removed by some unseen hand because they don't think you should be looking at it.

It's a world where you'll be milked by an array of methods for every penny you have to watch a movie, listen to a tune, use an application and whatever else.

The basic idea is to encrypt data and applications on your PC, then use a system of checks and 'trusted agents' to confirm the validity of these items before allowing them to be used.

Microsoft insists that this is an open system and that it will be the user who chooses to enable these features but, if applications coming from elsewhere require that it and third parties are determining the rules of access, what choice is the user left with?

And where will these 'trusted agents' come from anyway? According to Microsoft, the system is based on creating trusted holders of information who control the applications and data held on your PC.

Your PC is monitored by a new piece of silicon that will be integrated into processors from AMD and Intel, and which will check the state of your PC, applications and hardware and determine whether you have up-to-date licences. If not, you won't be able to use them.

The reason for all this was to help the operating system take control of copyrighted material. However, this vision has now spread to cover every aspect of your PC and seems to have been devised with US-based business objectives in mind. It's an example of how to capture markets, avoid piracy in places like China and the Far East and make more money out of PC users.

It's a chilling vision, but this announcement's has got out way ahead of its planned time. Microsoft hoped to launch Palladium next year. However, its well laid plan went wrong because US journalists discovered some patent applications for the concepts and asked the company what it was all about.

The technical implications and complexities are well described by others (see Ross Anderson's Q&A here), but every observer seems to agree that this a bad thing.

Microsoft's own explanation is available here and repeatedly reminds us that the technology can be switched off. But if we switch it off, exactly what will we be left able to do?

As well being a Microsoft vision, this concept ties in both Intel and AMD. If all three persist in pushing this concept, I suggest we stop buying the products as soon as they decide to incorporate the unwanted technology.

Maybe this is the boost that the Chinese chip industry and Linux needs to kick off as a viable alternative.

However, I hope Wintel/AMD realise this is a step too far in interfering in our privacy and freedom and step back from the brink. But maybe we're just seeing a process of expectation setting.

When the 'real' Palladium is announced and turns out not to be quite the Big Brother concept being represented at the moment, we'll all heave a sigh of relief. Yes, I must be getting paranoid.

Getting a better Linux user interface

Wayne Hazell — 2002-07-07T23:00:00.000Z

Wayne Hazell, PC Magazine, Sunday 7 July 2002 at 23:00:00

Wayne Hazell looks at various graphical user interfaces and how to install and configure them.

Beyond the basic kernel, Linux development is a free-for all with anyone able to write or adapt any elements of functionality they want for a system.

Given the fanaticism that graphical user interfaces (GUIs) generate across different platforms, it should come as no surprise that many people have tried to shape the structure of graphical environments for Linux.

For the sake of ease of use and consistency, the Windows and Macintosh operating systems have very strict, centrally administered rules governing how applications can be written and what standards must be adhered to in terms of functionality and appearance.

This is done with good reason: without them, there'd be a confusing mishmash of application and menu layout standards, with applications that appear inconsistent as a result of using different widget sets.

System resources would also be wasted by having to load multiple files that perform the same task. These problems haven't troubled most users since the pre-Windows era, when every DOS-based program had its own basic GUI and menu system that had to be deciphered on its own.

Now, however, it's taken for granted that Windows programs will function in a certain way. This type of centralised control was never going to be possible in the Unix world, so the system was designed from the ground up to be extremely open, extensible and configurable.

The downside is that, until the recent Gnome and KDE projects, the Linux desktop was convoluted, confusing and lacking in features.

The basis of Linux GUIs is a free implementation of the X Windows system called Xfree86. In one form or another X Windows provides basic functionality for practically all GUIs under the various flavours of Unix, with servers existing for Windows, Mac OS X and others. On top of X, a window manager is employed to draw the windows onscreen and display application data.

This is where the confusion begins, as there are many window managers available for Linux, with different features to suit most tastes.

This is all that's necessary for graphical computing, but most users opt to go the final step and run a desktop environment such as Gnome or KDE, which enforces a consistent look and feel to applications, as well as providing features like information embedding and drag-and-drop.

The X Windows system

Following the Unix philosophy, X Windows was built from the ground up to be a networked, multi-user, client/server graphical environment. As such, it does a lot more than simply draw pictures onscreen and this, perhaps, excuses some of its size and complexity.

Rather than being a part of the operating system, as with GUIs in other modern operating systems, X is just another server that sits on top of the kernel providing functionality.

Originally developed by the Athena Project in 1984, it came under the control of the X Consortium in 1988, which continues to administer and oversee its development.

The job of the X server is to communicate directly with the input devices and graphics hardware on the system, so all applications have to do is talk to the X server and it will take care of hardware input and display output without each application having to know anything about the display hardware.

X Windows doesn't just perform these tasks for a single machine, but allows multiple users to connect and display information from other devices across a network.

Users can log in to a central server and have all data displayed on a local thin client or run an application on one machine and have it displayed on another, including word processors, web browsers, output from a very intensive computation or image editors.

Hardware

X Windows not only displays output, but collects input to feed to applications, requiring keyboard and mouse compatibility, as well as display and video adapters.

Most of these are straightforward: X can handle most modern keyboards and mice, including PS/2, USB and infrared interfaces. Your video card determines the compatibility of the display, so any that can be driven by your graphics hardware will be perfectly happy with Linux.

The only difficult bit is making sure that X Windows is able to talk to your graphics adapter. There are many variants of the X Windows server, with each different type of graphics hardware requiring its own version.

While some cards can get away with a generic SVGA server, others require something more specialised, especially newer boards with 3D acceleration or advanced features.

The list of supported cards is quite long and extends right up to the most recent nVidia boards, although users are advised to check for issues with their specific hardware.

As most drivers are written by Linux enthusiasts and not the companies themselves, drivers often don't appear immediately on release of the hardware and special features might not be supported right away, if ever.

Supported cards are listed here, although vendor sites should also be checked.

Notebook PCs can also be problematic, as they often contain non-standard hardware that can't be changed. Specific hardware can be checked at www.linux-laptop.net.

Running X

Configuring X Windows has been made much easier in recent years. Distributions have tools that perform set-up during and after installation, in addition to the xf86config utility which comes with X Windows.

The main configuration file for X Windows is XFConfig or XFConfig-4 for Xfree86 v4 and above, which is generally found at /etc/X11/, although this might change between distributions.

This file contains the information that X needs to communicate with your display and graphics hardware. Generally, this file will be created by the distribution installer or a configuration program that can detect your hardware and set things up for you.

The adventurous can edit the file by hand to get non-standard resolutions (anything your hardware supports is OK) or fine-tune clock timings.

It's important to check the capabilities of your hardware before entering values here, as incorrect settings might damage your equipment. It's also a bad idea to simply drop in a config file from another machine, as it will almost certainly be set up for different equipment.

Aside from listing the devices and pointing to the proper drivers, the file contains a 'screens' section, which defines graphics hardware, resolution and colour depth.

There could be multiple entries here for different resolutions at which you might want to run. You can toggle through the resolutions while running X by hitting Ctrl-Alt-+ and Ctrl-Alt -. Separate applications, such as Gnome QuickRes, are needed to change colour depth on-the-fly.

Window managers

On its own, X can do little more than output pixels to screen, a process that would leave users with a grey, snowy background underneath an immovable xterm.

A window manager makes the display more attractive but, more importantly, adds several pieces of functionality, allowing the user to interact with X, drawing windows around applications and creating menu systems in their window.

In addition, many perform extra tasks, such as providing background wallpaper, controlling key bindings for mouse and keyboard shortcuts, launching programs either by a wharf/toolbar or by context-sensitive right-clicking, and multiple desktop functionality.

There are many available for free download, with a different range of features to cater for most tastes. At the lean end is fvwm, an 'old school' window manager that provides basic functionality with a very low resource footprint favoured by those who think that the best thing a window manager can do is stay out of the way.

At the other end is Enlightenment, which is designed to be extremely powerful and infinitely configurable. If you have a fast machine and love having weird, eye-candy desktops with unique themes and windows that aren't just boring rectangles, this could be for you.

Choosing a window manager used to be a near religious decision, as it controlled how you interacted with the computer, and dominated what you perceived a computer to be. Check out www.plig.org/xwinman/ for more information and pointers to the most widely used window managers.

These days, your choice might be dictated to some degree by whether a window manager is compatible with your desktop environment, such as Gnome or KDE.

Both function with their defaults and a few others, including Enlightenment and the popular Windowmaker, are among others available.

A window manager will still work even if it isn't supported by a desktop environment, but there might be conflicts over which draws the background or a context-sensitive right-click menu and some features might not work.

It's up to the user to decide what's most important to them. Many still load the libraries that allow them to run Gnome and KDE applications without running either environment, preferring to operate with just a window manager.

Desktop environments

Desktop environments for Unix have existed for many years, principally in the form of the not very attractive or functional and not free CDE. In recent years, Gnome and KDE have been getting a lot of press, as they've developed a lot of the functionality that allows Linux to compete with Windows on the desktop.

Without an environment, all applications run separately without any way to interact with each other, so there's no way to perform data linking and embedding or even simple drag and drop.

They also include taskbar equivalents that provide application launchers as well as a central location for resources, such as help and control panel access. Much of this functionality can be taken care of by the window manager, reinforcing the importance of having a window manager and desktop environment that work well together.

Desktop environments provide a consistent look and feel through the use of constant menu conventions and the same widget set, which also lessens the resource burden.

As with window managers, applications must be written to take advantage of the properties of a desktop environment. To this end, both Gnome and KDE have large lists of software for almost any purpose on their websites, with both going so far as to have full office suites in development.

Applications from a particular environment can still be run, even if you choose not to run it, as long as the proper libraries are installed on your machine.

Gnome and KDE work increasingly well with each other, for example importing the other's programs into each application launchers and allowing for interaction between the two systems.

Both are moving ahead with great speed: KDE has just released version 3 and Gnome 2 was scheduled for release in April 2002.

Launching X Windows

There are two common ways of launching X Windows. Traditionally, after logging in at the console, the user types in startx. This calls xinit, which launches X and looks for configuration files called xinitrc and xclients.

There will be general copies of these files for system-wide defaults (generally found in /etc/X11/xinit/), although each user can make a copy with personal preferences that will live in their home directory. Note that personal copies will exist as .xinitrc and .xclients, with the preceding full stop indicating a hidden file.

To display these files, type ls -al at the console, with the 'a' flag displaying hidden files. Xinitrc sets up the environment, configuring resources and performing tasks such as loading the proper keyboard mappings.

It will then check to see if there are any scripts that need to be run to launch other clients. Following this, it checks for the existence of an xclients file, either in the user's home directory or in a central location, performing the instructions in whichever it finds first.

In case no xclients file is found, failsafe instructions are included to launch a basic environment, in this case a clock, an xterm and the Netscape browser. Note how applications can be launched to appear at a certain position onscreen and with certain properties configured.

In this case, it controlls what page Netscape loads on launch although, similarly, you could set the background colour of the xterm, for example. After this, the script tries to load one of the more basic window managers that can be found on most systems; first the light, but functional, fvwm and failing that the truly spartan twm, which is better than nothing at all.

Preferably, all of this will be achieved by finding an xclients file. The xclients script first tries to launch a desktop environment, in this case Gnome or KDE. Preferences should be configured in a file but, if it can't be found, it will try to launch whatever it can find, in this instance trying Gnome first, then KDE.

If a desktop environment is found, it will take care of launching a window manager and default applications as specified by the user in the control panel of that environment. Failing that, it tries to launch a window manager, this time starting with Windowmaker, then recent variants of fvwm.

As with desktop environments, window managers have methods of launching applications. Again, when all else fails, it tries to launch twm and some basic applications. Commands can also be appended to the startx command, but it's easier to edit the config files or just perform the tasks once X has started.

The other, increasingly common, method is to use a display manager that launches X as part of the boot process so that the GUI is already running before you log in.

X comes with X display manager (xdm), with both Gnome and KDE having their own versions (gdm and kdm, respectively), which perform similar functions. In addition to launching X, this method can be used to define local, as well as remote, network 'displays' - the system by which X determines where to display applications.

This can be used to differentiate between using a notebook PC's built-in display against an external pane or whether to display an application on the local display or a remote desktop thousands of miles away.

Remote working

X is network aware and, while this makes it very powerful, it introduces problems of security and complexity. Where should applications be displayed? Who should get to see what is displayed on your desktop? Should other machines be allowed to write to your display?

X runs backwards to the normal perception of client/server. The server is running on your local machine, providing the graphics output. Each application is considered to be a client that connects to the server, sending it information to be displayed.

You can set X to accept or reject all connection attempts going in either direction. Given the security risks it's best to turn off all connections and enable them on a case-by-case basis.

When starting an application, X has to know where to send the output. By default, it will be sent to the local display, known as :0 (display 0). To have the application output sent to another place, it must be redirected to the hostname of that display.

For example, let's say that we perform our calculations on think.pcmag.co.uk, but want to display them on show.pcmag.co.uk. From 'show', you'd telnet into 'think' and enter:

Setenv DISPLAY

think.pcmag.co.uk:0

This tells it to display the output on display 0 (the default) of the local display.

Next, run the application Process_logs.pl &. Keep in mind that this will direct all output to show.pcmag.co.uk until switched off. A different method that's more compact and functions on a single-case basis would be process_logs.pl -display show.pcmag.co.uk:0 &.

The exact structure of the command can change depending on which shell you're running, but the display reference will remain the same.

Before doing this, you must set up the host, telling it to receive the request to display the data. Access to hosts can be given three ways. The easiest is to set it on the command line using the DISPLAY environment variable, which gives permissions based on hostname. In this case, we'd use:

Xhost + think.pcmag.co.uk

And when finished switch it off with

Xhost -think.pcmag.co.uk

The careless can simply set xhost + to allow anyone to connect (or xhost to bar all connections), although this isn't recommended for security reasons. For machines requiring frequent access, you can set up a hostnames file that allows access for some devices.

While easy to use, this method has a number of shortcomings, such as being unable to distinguish between different users on a remote machine and being susceptible to spoofing.

The second method is called Xauth, which uses a cookie system to control access. At the start of a session, the server reads a cookie and only allows access to remote systems with the same cookie. Provided you keep the directory with the cookie files in it secure, this is preferable to xhost.

Arguably the best solution is to forward your X session over a secure shell connection, which controls the log-in process and encrypts the data as it travels between the two machines. To use this method, either use the command line switch -X or enter the following into your ssh config file:

Host remote.host.name

ForwardX11 yes

If you don't want other machines to connect to yours, the most effective step is to add -nolisten tcp to the end of the main command in xserverrc. This will prevent the X server from listening for incoming connections and minimise the security risk. K

RESOURCES:

Here are some popular Linux distributors to check out:

Best Linux

www.bestlinux.net

Caldera

www.calderasystems.com

Conectiva

en.conectiva.com/

Debian

www.debian.org

Linux-Mandrake

www.linux-mandrake.com

RedHat

www.redhat.com

Slackware

www.slackware.com

SuSE

www.suse.com

Xandros (previously Corel Linux)

www.xandros.com