What is Linux?

What it is

Strictly speaking, Linux is the kernel, the core piece of software that talks to the hardware. It was started by Linus Torvalds and is now built by thousands of contributors, with the Linux Foundation supporting the project.

Companies and community projects package the kernel with other software into a distribution, or distro. Ubuntu and Debian are two of the best known. The code is open, so anyone can inspect it. Most distributions charge nothing per server. Red Hat Enterprise Linux is the main exception, sold as a subscription that includes support.

What businesses use it for

• File and application servers: hosting line-of-business software, databases and shared files.
• Web hosting: running websites, reverse proxies and mail systems.
• Virtualization and containers: the base layer for hypervisors and for Docker and Kubernetes.
• Appliances: firewalls, phone systems and storage devices often run Linux underneath.

How KawaConnect uses Linux

Our Linux work covers Ubuntu, Debian and RHEL-family servers. We build and maintain them, handle patching and monitoring, and write down how each one is set up. Our container platforms, Proxmox clusters and FreePBX phone systems all run on Linux too.

Learn more

• Linux on WikipediaThe history of Linux, how distributions relate to the kernel, and where it is used.
• The Linux Kernel ArchivesWhere the Linux kernel itself is published, with the current stable and long-term versions.
• Linux kernel documentationTechnical documentation for the kernel, mainly useful to administrators and developers.