This article tries to explain the differences between the major Linux distributions.
The Linux kernel comes from one source, Linus Torvalds himself. And
most of the other components come from one source too, the Free
Software Foundation. This is why fragmentation of Linux is very
unlikely. Each distribution is configured for a specific group of
users. Once you know the differences choosing a distribution is
largely a matter of personal taste.
The foremost area of difference is the packaging system. As
was mentioned earlier, the complete Linux system contains hundreds of
utilities and lots of applications. There are also libraries,
documentations, modules, etc. From now on we will refer to them as
components. Most such components contain multiple files. All
the distributions pack these files into a single file, known as a
package. Packaging allows for easy installation and upgrade. Currently
there are three major package formats, rpm - introduced by Red
Hat and used by most modern distributions, deb - primarily used
by Debian and tgz - used by Slackware. rpm and
deb systems maintain dependency information. If package A
utilizes or depends upon package B and you wanted to remove package B
or upgrade it in a way that breaks package A, the system will warn
you. Thus you can easily upgrade components of an rpm or
deb system without knowing their interrelations.
The startup or boot-up procedure of distributions also differ
somewhat. If you come from the DOS world you know it reads
config.sys and autoexec.bat at boot-up, they set some
configurations and run some commands. A Linux system is much more
complex than DOS/Windows, typically it reads several startup
files. These files are located in the /etc/rc.d
directory. The structure of this directory differs. There are two main
approaches, a Sys V style followed by Red Hat and Debian, and a BSD
style followed by Slackware. The Sys V followers use a lot of files,
sym links and sub directories. The BSD followers use only a handful of
files. We can have a war on which system is better, but actually
both have their merits, and each will appeal to different groups of
users.
Third comes the installation method. On thing for sure, each
distribution is trying to make this process more user friendly at
every release. All of them have some menu system to select the
components to install. One reason for Red Hats popularity is that it
was the pioneer in this field. By now, other distribution have
improved a lot, but many believe that Red Hat is still the easiest to
install. Debian had the the most unintuitive method up to its version
1.3. I haven't seen the newer 2.xx versions, debianites say that it
improved a lot. Slackware is in between the two extremes.
Fourth is the configuration methods. Red Hat and Caldera has some GUI
(read graphical point-n-click type) tools to configure various aspects
of the system, like printers, network, daemons, etc. These are helpful
for newbies coming from the Windows world. Slackware follows the
traditional Unix approach, you have to edit the configuration files
directly, but don't be afraid, these are not like the dreaded Windows
registry. All config files are simple text files and there are tons of
documentation. Unfortunately I don't know enough about Debian.
One issue that I can't explain here because of the limited scope of
this article is the C library, libc for short. It will suffice you to
know that there are two schools here, one that uses the new
glibc (also known as libc6) and the other uses
libc5. What will matter to you as a user is that, you can't
run a binary (executable) file compiled for one version of libc on the
other. This does not matter much because most distributions have
already standardized on glibc, and most Linux applications come as
source from which you can make binaries for either libc5 or glibc.
There are other issues like tech support and philosophy of the
organization that I will include in the next section.
Initially it became popular because of its ease of installation and
GUI point-n-click configuration tools. It uses the Sys V like startup
procedure. They are the creators of the rpm packaging system
which is followed by Caldera an many new distributions. This
distribution is helpful for newbies although I have some gruntles against this approach .
The latest version is 6.0 and uses kernel 2.2.x. The immediate
previous version is 5.2, which uses kernel 2.0.3x.
Because of the lack of GUI tools, it requires less space to install
too. It is also the distribution of choice for ISPs. Anyone who loves
the real Unix way, will love Slackware.
Slackware is the single major distribution that still uses the time
tested libc5. In spite of the advancements is glibc, it has some
problems, and lacks the test of time. Slackware also has the good
habit of distributing only matured tools and applications, thus avoiding
many security holes.
Slackware doesn't have the commercial flavour of Red Hat. The latest
version is 4.0 which uses kernel 2.2.x. The immediate previous version
is 3.6 with kernel 2.0.3x.
The FSF wanted to make the GNU (GNU is Not Unix) operating system, a
Unix like free OS. Thousands of volunteers made the components that
make a whole Unix system, but they failed to make the HURD, the kernel
of GNU OS. Development is still going on HURD, whether it will
ever see the light of day is a big question. We are very fortunate
that Linux came in just the right moment.
Debian is the only major purely non-commercial distribution. It uses
the deb packaging system, which many users claim to be better
than rpm. The biggest advantage of Debian is the HUGE
collection of tools, utilities and applications, all are free. This
distribution is especially suited for developers and power users.
The only problem with Debian, and this is a big one, is its package
installation program. Most people except the Debian fans describe it
as horrible. I personally don't think it is horrible but it certainly
is not easy, especially for newbies. Actually this package
installer does a lot more checking than its rpm equivalent and
it asks you to decide whenever it detects a possible problem, very
unlike rpm which will decide on its own what's vest for you,
and like any computer program it might not agree with you. Please
note that a new package installer has been included in the 2.x
series. I haven't checked it out yet.
Debian is maintained by volunteers through out the world. They also
have a very good bug tracking system. Debian got a boost recently when
Corel announced it will base its new distribution on Debian.
The latest version is 2.1. It has 4 CDs, 2 binaries and 2 source. This
is largely a bug-fix release to 2.0. The previous version is 1.3.x.
Caldera is an rpm based distribution. It is particularly targeted for
Novell Netware users. It has some GUI tools.
S.u.S.E. is gaining popularity. It bundles a lot tools and utilities.
If you don't want to know how the system works, and you are satisfied
with the limited choices a point-n-click tool gives you, in other
words, you are just looking for an alternative to Windows, Red Hat
will please you most.
If you are the opposite of above, i.e. you want to know how everything
works and you are brave enough to edit the configuration files by
hand, in short - you are looking for a Unix, Slackware is the
way to go. It will be your choice too if you are looking for the most
stable one of the three.
If you are a developer, you like the spirit of co-operation on which
Linux and the FSF is based on, and you don't mind editing
configuration files, Debian is a very good choice.
Point-n-click GUI interfaces are not only OK, but also THE way
to go for many people. If you are one of them, then you will be best
served by Microsoft Windows or a better alternative, the
Macintosh. Microsoft has done a lot of good things to the computer
industry and it is good in making pointy clicky interfaces. Just think,
why are PCs so darn cheap? because they have a huge market and
Microsoft has a lot to do in making this market. I don't see any good
reason why a secretary should dump MS Office and use Star Office. If
you can use a bit older version of Office, like Office 95, than you
get better performance than Star Office on similar hardware. Stability
is simply not a factor in such cases. It is foolish to even try
compare the graphics performances of Windows which is glued to the PC
architecture with that of X window which has to maintain portability
on countless platforms.
Unix is not for everyone. You will discover its powers only if you
have the inclination and the time to take the steep learning curve. It
is for people who don't want to be bound to a couple of radio buttons
an check boxes, those people who don't want to limit their thinking to
the metaphors of some windows, icons and sliders. Here is a good
article that tells you what type of people like Unix . Another
excellent article will tell you why people
love Unix . Novelist Neal Stephenson has an essay, In the Beginning was the Command Line
about the virtues of the command line.
Back to our issue, if you don't want or need the powers of the command
line, there is no reason to come to Unix/Linux. That is why I don't
like Red Hat. Slackware is simplistic, simplistic in the Unix way of
course. There is no mumbo jumbo gizmo, only the real Unix tools. Its
startup files are optimized for hand editing, unlike Red Hat in which
they are meant to be changed by the GUI tools, editing them directly
is possible but you will not like it and it may break the GUI tools.
I wouldn't have anything against Red Hat if everything could be done
in the GUI. It attracts people from the Windows world with its
perceived ease of use. Its a matter of time until they are thrown at
the command line and they discover that it's not all rosy underneath
and you hear them say "enough of this open source business".
My biggest gruntle is that it makes the newbies lazy and hides them
from the true powers of a Unix. I think new Linux converts should be
pointed to Slackware first. The not so newbies should help them as
best as they can. Only if they don't like this Unix way they
can be advised to look at Red Hat and other similar distributions.
Companies don't make a GPL release on CD directly. Almost all
distributions publish their work in ftp sites, other vendors like
Cheap Bytes and LSL download those distributions and burns them on
CDs.
So, which one should you use? If you are a business, please buy an
official release, this will help the Linux community. If you are an
individual and have a very tight pocket, a GPL release is good
enough. But please remember that buying an official version will be a
great help to the community, not to mention the nice packaging and the
manuals.
Vendors who sell both official and GPL releases
3. The major distributions
Though new distributions are coming constantly, probably more than 90%
use the major distributions. I don't know of any concrete statistics
on their usage. There is one at the Linux counter web site, but this a
bit out dated and somewhat flawed (1). Red
Hat seems to be the most popular at present. Slackware and Debian are
also prominent players. Caldera, S.u.S.E and Turbo Linux are the other
notable ones.
4. The differences
First of all, please know that I have experience mostly in Slackware, and
then Red Hat. I have only installation and a couple of days usage
experience in Debian. I haven't managed to get my hands on the other
distributions yet, my sketchy knowledge on them is only from articles/mails of
other people. So what I am saying in the rest of this article may not
be 100% accurate and it is certainly biased by my personal
preferences. And I will confess, I am most fond of Slackware, have
some gruntle on Red Hat and I am looking to switch to Debian. But I
will try to be as much impartial as is possible for a human
being.
5. Individual Distributions
Red Hat
Red Hat is enjoying the most popularity right now. The company is
being backed by heavy weights like Intel and Netscape. It has a strong
commercial mind set. They offer commercial tech support.
Slackware
This is one of the early starters. This is the most simplistic
distribution. It doesn't have any glitzy point-n-click config
tools. It follows a BSDish approach for the startup files. They are
laid out nicely, and anyone with a basic knowledge of bash can easily
edit them to suit their needs. In my opinion, configuring the startup
files in Slackware is much easier than the Sys V counterparts.
Debian
Debian is brought to us by the Free Software Foundation (FSF), the
organization without whom there wouldn't be any Linux. The bare kernel
made by Linus Torvalds would have served little purpose apart from
following the footsteps of Minix.
Others
Sorry! I don't have much information on other distributions. Here is
what I have gathered from various sources.
6. Which one to choose?
It largely boils down to personal preferences. The best way to choose
would be to try each one. But to know the pros and cons of a
distribution you need to use it for some time. If you don't have the
time or inclination, here is my short list.
7. My personal preference
I have some gruntles against the point-n-click ways. I have some harsh
things to say, so please note that these are my personal opinions and
you can just skip this section.
8. Official and GPL releases
Most distributions come in two flavours, an official and a GPL'ed or
free release. Official releases cost a bit, from around $50 to more
than $100. GPL releases cost as little as $2 per CD. In most
distributions there are no differences apart from a printed
manual. Distributions like Red Hat and Caldera contain a few non free
applications in the official release. Red Hat and some other companies
also give you tech support for some time if you purchase the official
release.
9. Vendors
Here is a list of web sites of distribution makers.
10. Last words
The question which Linux distribution is best is not very
meaningful as there is no answer for it. Certainly don't ask this
question on any mailing list or newsgroup, there are fanatics
everywhere and the Linux community is no exception, I can guarantee
you a lot of flame mails for this question. No one OS fits all, and no
one distribution will fit all. Ultimately, the best distribution for
you is the one you like best.
Footnotes:
Last modified: May 28, 1999