Textbook of Linux

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Linux kernel

The kernel at the heart of the Linux operating system.

The Linux kernel is the core program that mediates between hardware and everything else: it schedules processes onto CPUs, manages memory, organises file systems, and routes network packets. Linus Torvalds announced the project on Usenet in August 1991 as a personal hobby and released it under the GPL the following year.

The kernel has grown into one of the largest collaborative software efforts in history, with thousands of contributors per release cycle. Its development happens through a distinctive review-based process anchored around the kernel mailing list and coordinated via Git, which Torvalds wrote specifically for this job after the project lost access to its previous version control tool.

The kernel runs on a wider range of hardware than any other operating system: from tiny embedded devices to the largest supercomputers, including every machine on the TOP500 list as of 2024.

The kernel ships with every Linux distribution; you do not install
it directly. To compile from source:
  git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
  cd linux && make menuconfig && make -j$(nproc)