RedHat

RedHat, assembled by the company Red Hat, was a popular Linux based operating system until its discontinuation in 2004.

Red Hat Linux 1.0 was released on November 3, 1994. It was originally called "Red Hat Commercial Linux It was the first Linux distribution to use the RPM Package Manager as its packaging format, and over time has served as the starting point for several other distributions, such as Mandriva Linux and Yellow Dog Linux.

Since 2003, Red Hat has discontinued the Red Hat Linux line in favor of Red Hat Enterprise Linux (RHEL) for enterprise environments. Fedora, developed by the community-supported Fedora Project and sponsored by Red Hat, is the free version best suited for home use. Red Hat Linux 9, the final release, hit its official end-of-life on 2004-04-30, although updates were published for it through 2006 by the Fedora Legacy project until that shut down in early 2007.

Feature

Version 3.0.3 was one of the first Linux distributions to support Executable and Linkable Format instead of the older a.out format.

Red Hat Linux introduced a graphical installer called Anaconda, intended to be easy to use for novices, and which has since been adopted by some other Linux distributions. It also introduced a built-in tool called Lokkit for configuring the firewall capabilities.

In version 6 Red Hat moved to glibc 2.1, egcs-1.2, and to the 2.2 kernel. It also introduced Kudzu, a software library for automatic discovery and configuration of hardware.

Version 7 was released in preparation for the 2.4 kernel, although the first release still used the stable 2.2 kernel. Glibc was updated to version 2.1.92, which was a beta of the upcoming version 2.2 and Red Hat used a patched version of GCC from CVS that they called "2.96". The decision to ship an unstable GCC version was due to GCC 2.95's bad performance on non-i386 platforms, especially DEC Alpha. Newer GCCs had also improved support for the C++ standard, which caused much of the existing code not to compile.

In particular, the use of a non-released version of GCC caused some criticism, e.g. from Linus Torvalds and The GCC Steering Committee; Red Hat was forced to defend their decision. GCC 2.96 failed to compile the Linux kernel, and some other software used in Red Hat, due to stricter checks. It also had an incompatible C++ ABI with other compilers. The distribution included a previous version of GCC for compiling the kernel, called "kgcc".

As of Red Hat Linux 8.0, UTF-8 was enabled as the default character encoding for the system. This had little effect on English-speaking users, but enabled much easier internationalisation and seamless support for multiple languages, including ideographic, bi-directional and complex script languages along with European languages. However, this did cause some negative reactions among existing Western European users, whose legacy ISO-8859-based setups were broken by the change.

Version 8.0 was also the second to include the Bluecurve desktop theme. It used a common theme for GNOME-2 and KDE 3.0.2 desktops, as well as OpenOffice-1.0. KDE members did not appreciate the change, claiming that it was not in the best interests of KDE.

Version 9 supported the Native POSIX Thread Library, which was ported to the 2.4 series kernels by Red Hat.

Red Hat Linux lacked many features due to possible copyright and patent problems. For example, MP3 support was disabled in both Rhythmbox and XMMS; instead, Red Hat recommended using Ogg Vorbis, which has no patents. MP3 support, however, could be installed afterwards, although royalties are required everywhere MP3 is patented. Support for Microsoft's NTFS file system was also missing, but could be freely installed as well.

Red Hat Enterprise Linux

Red Hat Enterprise Linux (RHEL) is a Linux-based operating system developed by Red Hat and targeted toward the commercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64. All of Red Hat's official support and training and the Red Hat Certification Program center around the Red Hat Enterprise Linux platform. Red Hat Enterprise Linux is often abbreviated to RHEL, although this is not an official designation.

The first version of Red Hat Enterprise Linux to bear the name originally came onto the market as "Red Hat Linux Advanced Server". In 2003 Red Hat rebranded Red Hat Linux Advanced Server to "Red Hat Enterprise Linux AS", and added two more variants, Red Hat Enterprise Linux ES and Red Hat Enterprise Linux WS.

While Red Hat uses strict trademark rules to restrict free re-distribution of their officially supported versions of Red Hat Enterprise Linux, Red Hat freely provides the source code for the distribution's software even for software where this is not mandatory. As a result, several distributors have created re-branded and/or community-supported re-builds of Red Hat Enterprise Linux that can legally be made available, without official support from Red Hat. CentOS and Oracle Linux aim to provide 100% binary compatibility with Red Hat Enterprise Linux.

Variants

There are also "Academic" editions of the Desktop and Server variants. They are offered to schools and students, are less expensive, and are provided with Red Hat technical support as an optional extra. Web support based on number of customer contacts can be purchased separately.

It is often assumed the branding ES, AS, and WS stand for "Entry-level Server", "Advanced Server" and "Work Station", respectively. The reason for this is that the ES product is indeed the company's base enterprise server product, while AS is the more advanced product. However, nowhere on its site or in its literature does Red Hat say what AS, ES and WS stand for.

In Red Hat Enterprise Linux 5 there are new editions that substitute former Red Hat Enterprise Linux AS/ES/WS/Desktop:

• Red Hat Enterprise Linux Advanced Platform (former AS)
• Red Hat Enterprise Linux (former ES) (limited to 2 CPU-s)
• Red Hat Enterprise Linux Desktop with Workstation and Multi-OS option
• Red Hat Enterprise Linux Desktop with Workstation option (former WS)
• Red Hat Enterprise Linux Desktop with Multi-OS option
• Red Hat Enterprise Linux Desktop (former Desktop)

Red Hat had also announced its Red Hat Global Desktop Linux edition "for emerging markets".

RHEL 4, 3, and prior releases had four variants:

• Red Hat Enterprise Linux AS for mission-critical/enterprise computer systems.
• Red Hat Enterprise Linux ES for supported network servers
• Red Hat Enterprise Linux WS for technical power user enterprise desktops for high-performance computing
• Red Hat Desktop for multiple deployments of single-user desktops for enterprises.

“Both Fedora and Red Hat Enterprise Linux are open source. Fedora is a free distribution and community project and upstream for Red Hat Enterprise Linux. Fedora is a general purpose system that gives Red Hat and the rest of its contributor community the chance to innovate rapidly with new technologies. Red Hat Enterprise Linux is a commercial enterprise operating system and has its own set of test phases including alpha and beta releases which are separate and distinct from Fedora development.”