Red Hat Enterprise Linux is a commercial Linux operating system sold by subscription. It was initially distributed for free under the name of Red Hat Linux, but discontinued in the year 2003 when the project was split into Fedora Core and RHEL. It is a pioneer operating system, as it was the first to use the highly-acclaimed RPM (Red Hat Package Manager) software to install, update and remove packages.
Inspiration for the Fedora and CentOS projects
Until version 6.1, Red Hat used a text mode installer for its Linux distribution. However, in 1999 the company developed the Anaconda graphical installer, which was intended to allow novice users to install the operating system. Both RPM and Anaconda technologies are now used in many popular operating systems, including Fedora Linux and CentOS. The latter is an open source flavor of RHEL (Red Hat Enterprise Linux) based on its publicly available source packages (SRPMS).
Distributed in multiple editions
The operating system was always available as Workstation, Entry-level Server and Advanced Server editions. Recent editions include RHEL Advanced Platform, RHEL Desktop with Workstation and Multi-OS option, RHEL Desktop with Workstation option, RHEL Desktop with Multi-OS option, and RHEL Desktop.
Academic editions of its Workstation and Server flavors are also available for purchase. The distribution used and it still uses GNOME as its default desktop environment, since the release of Red Hat Linux 6.0.
Default applications
Default applications include the Mozilla Firefox web browser, GIMP (GNU Image Manipulation Program) image editor, Inkscape SVG graphics editor, K3b CD/DVD burning tool, and the LibreOffice office suite.
Among other software packages, we can mention the Mozilla Thunderbird email/newsgroup client, MariaDB database engine, OpenJDK, OpenSSH, OpenSSL, Perl, PHP, Postfix, PostgreSQL, Python, Qt, Samba, systemd, XOrg Server, and Vim (Vi Improved) advanced text editor.
Bottom line
As mentioned, Red Hat Enterprise Linux is a pioneer operating system. Today, it is used in well known organizations, commercial vendors, and companies from the IT business.