Linux Distributions

The simple answer is that there isn't a "best" distribution. Opinions vary, so we can't recommend a "best" distribution. But we can give you some guidelines.

The kernel:

• is the most basic part of the operating system;
• is what makes the operating system Linux, instead of HPUX, Xenix or some other Unix variant;
• is really the operating system itself; anything your programs or you want to do with your hardware goes through the kernel, which interprets what you or your program wants and executes it in the hardware;
• was originally written by Linus Torvalds in 1991, and is still maintained by him;
• has various version numbers, just like any other software; the version number of the kernel in your distribution doesn't really matter, as version numbers change slowly and there isn't that much difference in the kernel version numbers from one distribution to the next.

Along with the kernel, a distribution will come with a variety of "utility" programs that enable you to create new users, copy files, or do any of the other things you'd do with a computer. Most of these programs are the same programs that come on any Unix system. Linux and Unix use a "tool-based" approach to these programs. They do one thing, and do it very well. A "hammer" program would just do hammering, and a "wrench" program would just do wrenching.

Distributions often come with "commercial" programs (programs that would cost you money if you bought them separately), or "suites" of programs, like bundles of word processors, spreadsheets and drawing programs. This is one way that distributions add value and make their products stand out from others.

Unlike just a few short years ago, Linux distributions now are quite polished and suitable for people familiar with other popular operating systems.

• Popularity or market share.
• Hardware detection capabilities.
• Ease of installation and management.
• Package management facilities.
• Programs that add value.

Of the above, package management is the only one that truly needs clarification. When you install a program on a Linux computer (and this is true on DOS/Windows machines as well), you are usually installing more than just one executable file. There are initialization files, data files, libraries of executable code, etc. If you had to install all these by hand, it would be worse than any kid's bike you ever put together on Christmas Eve. The solution to this is to put everything in a "package" and install the package. (In a DOS/Windows environment, this is generally one or more diskettes or a CD-ROM; you need never know all the things that got put on your computer.)

"Installing" a package puts all the little files where they should go on your system, and if done right, the system remembers where it put everything. Later, if you go to "upgrade" your package (install a more recent version), it simply repeats the process.

One of the important things about package management is that often when you install a program, it requires other "libraries" of code to exist on your system somewhere. The new Gee-Whiz program may require the Oh-My-Gosh library to be installed before it will work properly. There are several reasons why this is works this way. Let's say that you build this nifty library of code that handles the keyboard, mouse and screen-painting for programs, and other programmers think this is a great library to use. So when they write programs, instead of writing all that user-interface code, they just put in a call to your library: "Hey, move the mouse over to the left about an inch!" The advantages here are that the other programmers don't have to write all this code over again themselves, and they can keep the size of their programs small by not including all that code. The disadvantage is that you have to have this library on your computer before the new program will run.

Package management systems handle this by ensuring that you have all the right libraries for your package on your computer before they install things. And sometimes, they will even allow you to go on the internet and download the missing libraries.

Now that you know something about what makes distributions different, we can (finally!) get to the main distributions.

Red Hat used to be the most popular Linux distribution. They originated the Red Hat Package Manager (RPM) package format. In the last few years, they had an IPO, and recently they've eliminated their desktop product, in order to concentrate on their (expensive) enterprise server products. They have not cut their ties to the Open Source community entirely. They now have a distribution called "Fedora". This distribution is still managed by Red Hat, but relies on community involvement, and has no support from Red Hat. It is free, but has some rough edges. When its code is mature, parts of it will be rolled into the enterprise server products. This distribution contains all the things you would expect-- the Apache web server, word processors, spreadsheets, a GUI environment (X Window) and more.

Slackware is a well-known distribution that used to be the most popular distribution until Red Hat came along. It is put out by one guy: Patrick Volkerding. It models itself more after traditional Unix than any other distribution. Installation is not too bad, but it helps if you have prior Unix experience with building a system. The biggest drawback to Slackware is that it does not have a mature package management system. The word "mature" is emphasized here. Only recently has Slackware developed the ability to manage packages, but the software to do this is still inadequate compared to other package management software. Note that the "package installation" process is something you do not have to go through when you are first installing Slackware; it figures all this out for you the first time around. But roll your sleeves up and prepare to hack configuration files to alter this system once installed. Real men choose Slackware.

Debian is built, tested, and put out by volunteers. It is very strict about adhering to "standards", like what goes in the /etc directory and so forth. Updates to this distribution sometimes take a painfully long time to come out, but are extensively tested by hundreds of volunteers before being committed to plastic. Part of the reason for this is that the Debian Project does not have a revenue stream to feed. The up side to this is that it is probably the highest quality and most stable distribution out there. However, Debian's install procedure can be very tedious, and can take hours to complete. Debian has a package management system that is excellent, but is not compatible with that of any other distribution. The effect of this is that RPM packages are easier to find than DEB packages. There are tools that allow Debian to read RPM files, but that, too, is a tedious process. Debian also has the best online help of any distribution. It has a tool that allows you to view standard man and info files as HTML files in a browser. A testament to the quality of the Debian distribution is the fact that many of the most successful and well known distributions today are based on Debian. The Debian distribution itself is perhaps second only to SuSE in the amount of software available in it.

SuSE, a distribution put out by a German company (now owned by Novell), is the most popular Linux distribution in Europe. It comes with one of the most extensive sets of software of any Linux distribution, primarily because in Europe they pay for internet access by the hour. Thus, it's cheaper for customers to get all their software on CD or DVD than to download it. It is well engineered and has excellent hardware support, particularly for X Window and laptops. It also has the best paper documentation of any Linux distribution. It has some proprietary programs, like YaST, that make administration of a SuSE box relatively simple. It uses RPM packages. While this distribution is commonly available at places like CompUSA, support for it is not good here in the U.S. However, as with most Linux distributions, it has an active online support community.

Mandrake is a distribution originally based on Red Hat, but designed to be much more user friendly. Though this is a capable distribution, it is best used by newbies. "Old hands" often find it too "dumb". Mandrake is effectively controlled by a non-profit in France, and has had difficulty with its financing in recent years. Hard core Mandrake users donate to Mandrake to keep things going.

TurboLinux is the largest distribution in the Orient and Far East, and has built-in support for large character sets (like Japanese Kanji). It is not well-known in the US, and updates seem to be slow in coming.

Gentoo is a distribution that's gaining a lot of converts. However, it is not for the faint-hearted. It often requires the building of software from source code, though its package management system does make this somewhat easier.

Mepis is a distribution based on Debian and designed to resolve some of the problems of Debian, mainly S-L-O-W upgrade cycles. The person who designed Mepis made a great many design decisions that eliminate software from Mepis. This means that instead of coming on seven or more CDs, it comes on two. However, it is fully functional and has good hardware support. It is not flashy, but very functional.

Xandros is another Debian-based distribution, with some of the best hardware detection and support in the field. It is attractive, but like Mepis, comes on far fewer CDs than Debian. It is not free, and is built and distributed by an actual company.

Knoppix is a one-CD distribution built in Germany and designed to be a fully functional "demo" distribution. When you pop the CD in and reboot your machine, a fully functional and attractive Linux distribution comes up. The big advantage of Knoppix is that it does not disturb whatever operating system you already have on your computer. It can also be used as a troubleshooting tool for systems where you suspect some hardware fault. It is based on Debian and has very extensive hardware detection capabilities. It can be installed on your computer, and this is being done more and more by users as time goes on.

Lindows/Linspire is another Debian-based distribution, similar to Xandros. In fact, it uses many of Xandros' software libraries. This distribution is sold on inexpensive computers at Walmart. The system comes with a bare minimum of software. It is expected that the user will subscribe to Lindows' software subscription service for a yearly fee, and download whatever they like off of Lindows' servers. Recently this company was sued all over the world by Microsoft for the use of the name "Lindows". Naturally, these lawsuits have far less to do with Microsoft's concern over possible infringement of its trademarks, and far more to do with Microsoft's desire to block Linux at any opportunity. As a result of these lawsuits, Lindows has changed the name of its distribution to "Linspire".

Linux From Scratch isn't so much a distribution as a document that tells you, step by step, how to put together a Linux distribution. You follow along in the document, download software packages, and compile and install them yourself. In the end, you have a minimal, but functional, system lacking some things, like X Window. This "distribution" is really meant as a teaching tool (self teaching). There are follow-on documents like "Beyond Linux From Scratch", which take LFS a step further and instruct you in the downloading, compiling and installation of more advanced software, like the X Window GUI system. Using these, you can have a system tweaked for your particular hardware and fully as capable as other distribution.

Others. There are probably hundreds of Linux distributions, all based on the same kernels, but including different software tools and applications, and incorporating varying degrees of facility in operation and management. Some are specifically designed for use on gateways, routers and firewalls. Some are geared to a specific language or geographical part of the world. Most of the variations on the above distributions exist to answer a specific need or scratch a specific "itch"; that is, to do one or more things "better" than an existing distribution.

The above seem to be the most popular distributions. (Things change from time to time.) New Linux distributions seem to come out every week. The most complete list of distributions is probably at DistroWatch.com.

On this page, you'll find links to some of these distributions and to places that sell these distributions.

Paul M. Foster