Linux Guide/Distros in detail
Arch Linux is a relatively young distro which offers more comfort than Slackware in that most things have reasonable defaults, the software does already work together within reasonable limits (so it's not "over-configured" like the big distros) and you can choose between binary package installation (with dependency support) and source compilations.
Debian was considered one of the harder distros to install, although with the release of 'Sarge' this has now improved due to a new installer. The installation is not too hard for the prepared user and what difficulties it may still cause is made up for by apt-get: a package management system that automatically downloads and installs or upgrades programs. It can even upgrade the entirety of Debian when it becomes necessary, so a computer running Debian will never need to be totally reinstalled for an upgrade.
Debian is popular enough that a very large number of packages are available for it — virtually every common open source program (and many libre closed-source ones) has a package made for it. However, the "stable" distribution is usually very outdated (they come out about every two years), so many home users will opt for the "testing" or "unstable" versions which come with more up-to-date software. Unstable is updated more quickly, but the official policy on it is "if it breaks, you get to keep both parts." Nonetheless, it is much more stable than the name implies.
Debian is entirely non-commercial, and only software that meets the Debian Free Software Guidelines(direct) makes it to the main distribution. However, it is made easy to install non-free software with the same tools if you need it.
Debian is among the most widely ported distributions. Unlike other distrobutions which usually only run on x86 and x86_64 hardware. Debian has official ports to SPARC, alpha, powerpc, arm (big and little endian), mips (big and little endian), PA-RISC, IA-64, s390 (IBM mainframe), x86, and x86_64. There is also a community port or Motorola m68k. It can take full advantage of almost any hardware you have. Unlike other distributions, Debian also releases optimized kernels for more specific releases of processors.
Debian is known for extremely high quality releases, which are very stable.
Some people have hardware that isn't recognized by the "easy" installers from any distribution. If you are one of those people, check out non-official Debian installers that are designed to run on the widest possible variety of computers here.
Debian's wiki is at http://wiki.debian.org/
Debian's main site is http://debian.org/
Gentoo is a source-based distro. It is far more time-consuming and difficult to install than any other major Linux distribution. This is primarily due to it lacking an installer; it merely provides "stage tarballs" and boot CDs. The CDs provide a basic environment for bootstrapping the system; they include packages necessary for install, drivers, a shell, and not much else. There is no graphical installer, nor even a text based one, despite several plans for creating one; the command line is used for the whole install.
Gentoo is not a distribution for any but the most technically oriented - not those necessarily who are already familiar with GNU/Linux (also called Linux), but for those who want to learn more about how a Linux system works. It is a highly flexible system, which can be tuned to every user's individual needs; this comes at the price of being somewhat more hands-on. There is far less autodetection than in other major distributions. Furthermore, most programs must be compiled from their source code. Fortunately, Gentoo's documentation site contains comprehensive documentation on an expanding number of topics. It has a very good installation guide, which is now the "Gentoo Handbook", which teaches new users several things about the structure of Gentoo and how it works. There is also a Gentoo Wiki
The installation process is long, especially if source packages are used. Binary packages are possible, and can be provided either from GRP or custom-made, but are not frequently used. Installation is an involved process, but not especially difficult to those who carefully follow the installation guide; help is provided in numerous ways to those who have trouble, whether the cause is unfamiliarity with the system, custom needs, or shortcomings in the install process. The installation guide provides highly detailed examples, complete with sample commands which often work unchanged, and include directions of how and what to change for highly variable details such as which hard disk partition to use.
Gentoo has a steeper learning curve than other distributions of Linux. This is both a cost of the flexibility, combined with the fact that Gentoo does not have a long history (so sometimes suffers from not entirely automating what should be automated). This is mitigated somewhat by the documentation and huge amount of community support, including very large forums. Many questions on the forum get answered very rapidly. The reason for the large forums is that just about everyone who uses it is in love with it, largely due to its advanced package system, "portage".
Portage is source-based, and also supports quarterly binaries for those who would rather not do compilations. The package system is inspired by BSD's "ports" system, and shares some similarities to Debian's package system, such as automatic dependency resolution (which means, in short, that anything you need to compile/install a package will be automatically installed when you ask the system, with "emerge name-of-package", to do so; this contrasts with the historical frustrations presented to users of package systems where each dependency must be manually found and installed first. How to install each package is described by a simple machine-readable text file, called an "ebuild". Ebuilds are conceptually simple, but can become quite complex, and provide Gentoo-specific configuration for packages; they also frequently apply patches which increase functionality or fix bugs. Major packages (which have the best-maintained ebuilds) are consequently easy to upgrade and most start with a working configuration; further details on what a user may want to do are shown after a package is installed. There are around 7000 packages available in portage, and on average 50 new packages (including upgrades) are added daily. The newest updates can be seen on the "Fresh Ebuilds" site.
Gentoo is most likely to be appreciated by people with fast computers and Internet connections, due to the bandwidth and processor-intensive nature of its package system. Those with unusual needs may also appreciate Gentoo; as Linux changes rapidly, and Gentoo is highly configurable, it can make some tasks easier than other distributions do. A typical Gentoo user wants to know exactly what makes up their system and appreciates major configurability. Gentoo systems are easy to keep very up to date; unfortunately, some stability is often sacrificed, especially in the "~arch" [similar to Debian's "unstable"] branches.
Gentoo is least likely to be appreciated by those with slower computers and Internet connections, unless they are highly patient; if an advanced package manager is wanted, these users may prefer BSD or Debian. Users who want a Linux system to just work with no manual configuration are more likely to at least initially appreciate a distribution such as Lycoris, Xandros, or perhaps Mandrake or Fedora Core.
Red Hat gears the majority of its production toward corporate clients. However, a frequently updated consumer edition, Fedora, is offered. It is a popular distribution built by a community under the central direction of Red Hat, and its code is the basis from which Red Hat's enterprise software is developed. While Fedora is easy to use and has very good graphical utilities (including an installer), it's still a flexible and powerful distribution, capable of everything from laptop computing to a full-fledged multi-use server to a thousand-node cluster, and beyond. The package manager, RPM, does not automatically handle dependencies, however it is quite popular and many Linux applications are available as pre-compiled RPM packages; also, users may opt to use yum or PackageKit, both included with Fedora, to install packages instead. They may install the alternative installers apt-rpm and synaptic. Ten versions of this distro have been developed among which Fedora 11 is the latest available at the official website. Previous versions were Fedora Core 1, 2, 3, 4, 5, and 6, and Fedora 7, 8, 9 and 10.
Mandriva was originally known as Mandrake. It was originally based on Red Hat; it is now a distribution in its own right and is designed for beginners and experts. Mandrake's installation program has the ability to resize NTFS partitions, meaning it is a good choice if you want to keep your existing Windows XP or Windows 2000 installation but still install Linux (however, Knoppix can be used to resize NTFS partitions before an installation no matter what distro is being installed).
Mandriva uses the urpmi package manager, an equivalent of apt-get for rpm packages. Urpmi has both graphical (see screenshot here: ) and text-based front-ends. With the graphical front-end it is very easy to manage all installed and available software.
The live-version of Mandriva is MandrivaOne, which runs KDE or GNOME, has a one-click installation method. The installed Linux is the Official Mandriva Linux 2007, which makes for easy update/upgrade/program installations.
"Live-CD", installable, Recordable DVD
Q: Is it true that this can run on a PC that doesn't even have a hard drive?
A: Yes - true. It will run on older hardware. It will run from USB keydrive. It works like Windows. You can run it from Windows You could even remove the CD ROM and floppy and have a machine with no hard disk no CD ROM even. It also can be run from a CD-RW. When you finish a session it writes any files to the CD-RW or DVD-RW
Puppy Linux can also be installed to a hard drive in the traditional way and the "install it to files on a vfat partition" way.
Sabayon is a binary Gentoo distro. This is the recommended distribution for those who want to learn Linux or use bleeding edge software. A typical DVD installation 1hr with an 8x DVD drive. Gentoo's the distribution with the sharpest learning curve because it requires knowledge of the hardware and compiling the kernel first thing. Sabayon is just the opposite of Gentoo except that it's still Gentoo, which is designed for optimizing your applications by compiling them from source. Sabayon comes with a kernel configured for all kinds of hardware along with precompiled binaries. The Gentoo Portage package manager is still there for optimizing your favourite applications and giving them a boost.
Slackware tends to be favored by the more hardcore Unix fans. The entire operating system is based around tarballs and source installs. It definitely is a Linux distribution which requires the user to have a solid knowledge of the filesystem and its operations. It is not typically recommended for first time users, and should be installed by people with a desire to know the deeper and more complicated problems that arise within the Linux world. The install set typically is 4 cd's with 2 of them being a store for source tarballs and other packages. The opinion of some is that Slackware tends to be a more rock solid Distro, with less security vulnerabilities. Some first-timers consider it to be easy to install, but this is usually because they have worked with other UNIX-like OS's before. Installing it is quite simple, however configuring it to your liking is much more difficult. Slackware likes to have manual controls, so the user may find oneself using the terminal more often, needing to manually mount devices, etc. A large and growing number of Linux users have abandoned Slackware for newer, more advanced and overall less needy distributions.
Slackware does have support for other package modules, mainly RPMs. However, this support is limited, and without support generally. It's better suited to install applications by source compiling. Slackware is a good choice, but a user should probably be well versed in Linux prior to giving it a shot, it's not a bad learning distro, just a hard distro to learn.
SuSE is mostly popular in Europe and was acquired by Novell in November of 2003. SuSE focuses, like Mandriva, on an easy installation procedure and graphical administration tools. A graphical installation program guides you through the individual steps necessary to install Linux.
The SuSE Linux distribution is updated regularly and was chosen by many cities in Germany like Munich, to convert their desktop and server computers to Linux.
SuSE has possibly the best installer software of any Linux distribution, called Yast , which they recently (mid 2005) released as GPL (open source).
SuSE is a stable and easy to install Linux distro. And is by default LSB(Linux standard base) compliant.
Also SuSE like most other distributions is available on the form of downloadable ISO files (which you can write to CDs or a DVD). For this purpose you can use this link http://www.opensuse.com
It is usually available the same day as it is released in the stores. If you want installation support you must pay a one time fee for 90 days support. Earlier, before the openSuSE project you would have to wait for 3 months before the ISO of the latest version was available.
Ubuntu & derivatives
Ubuntu is a desktop Linux distribution. It is based on Debian and copies over many Debian packages.(albeit many outdated) Ubuntu is sponsored by Canonical Ltd, however all releases are free of charge. The name of the distribution means "humanity towards others". New versions are released every 6 months, and support (bug fixes) is provided for 18 months after the release. Ubuntu is developed for x86 and x86_64 systems.