Linux Variants: Ubuntu, Kali, Debian, Red Hat, Fedora & CentOS…

With numerous Linux distributions like Red Hat, CentOS, Debian, and Ubuntu often mentioned, it's easy to get lost in the mix. This guide aims to clear up your confusion and help you better understand the Linux ecosystem.

1969 The Birth of UNIX

1969: Ken Thompson and Dennis Ritchie develop UNIX at Bell Labs

1973: UNIX is rewritten in C, improving its portability

1975: AT&T begins distributing UNIX source code to universities

1997 Commercial UNIX: BSD

1977 BSD (Berkeley Software Distribution)

Descendants: FreeBSD, OpenBSD, NetBSD

1980s SunOS, AIX

GNU Project & Linux

1983: Richard Stallman starts GNU project
- Aimed to create a free UNIX-like system
- But lacked a crucial kernel

1991: Linus Torvalds publishes Linux kernel
- Initially developed as a standalone project, not for GNU

1992-1993: Early Linux distributions combine GNU tools with Linux kernel
GNU tools + Linux kernel = Complete OS. This combination became known as "GNU/Linux"
they are happy together

Major Linux Variants

That’s crazy.

Debian (1993)

Community-maintained

derivatives:

Knoppix (2000)
- Kali (2013, security-focused)

Ubuntu (2004, company-supported)
- Kubuntu,Xubuntu, Lubuntu…

Red Hat (1994)

Red Hat Enterprise Linux (RHEL, 2002)
- Fedora (2003, community version, RHEL testbed)

CentOS (2003, open-source RHEL clone)

SLS (1992)

Slackware (1993)

SUSE (1994)
- openSUSE (2006, community version)
  - Targets users who prefer frequent updates, but with potential stability trade-offs
- SUSE Linux Enterprise Server (2000)

`Arch` (2002)

Known for its package manager, pacman (yes, that game)

`Alpine` (2006)

Popular for minimal Docker images

Package Management

OS	commands	low-level commands note
Debian/Ubuntu	`apt` (new), `apt-get`	`dpkg` (it doesn’t care dependencies issues)
Red Hat/Fedora/CentOS	`dnf` (new, RH v8+), `yum`	`rmp` (Red Hat Package Manager, old) (it doesn’t care dependencies issues)
Arch	pacman
macOS	homebrew