v0.01 · Sep 17, 1991
Linux Born
Torvalds uploads v0.01 to Helsinki University FTP. 10,239 lines of code. Requires Minix to compile.
Originv0.12 · Jan 1992
GPL v2 Adopted
Torvalds switches to GPL v2 — allowing commercial distribution while guaranteeing open-source status permanently.
v1.0.0 · Mar 14, 1994
First Stable Release
176,250 lines of code. Supports single-processor x86. GNU Project adopts it as the kernel for GNU/Linux.
Milestonev2.0 · Jun 1996
Multi-Processor Support (SMP)
Symmetric multiprocessing added. IPv4 networking stack matures. Linux gains traction in servers.
v2.6 · Dec 2003
The Decade-Long Kernel
Virtualization, SELinux, improved threading (NPTL), inotify. 2.6.x runs for 8 years through hundreds of sub-releases.
Server DominanceAndroid · 2008
Linux Powers Mobile
Google's Android launches on modified Linux 2.6 with Binder IPC, wakelocks, ashmem. Now on 3B+ devices.
v5.x · 2019–2022
io_uring, WireGuard & Security
io_uring async I/O. WireGuard VPN merged mainline. Spectre/Meltdown mitigations. eBPF observability framework.
v6.1 · Dec 2022
Rust Enters the Kernel
Rust becomes second supported language for kernel development — improving memory safety in drivers. LTS through 2026.
LTSv7.0 · Apr 12, 2026
Latest Stable
Continuing evolution: Rust driver expansion, advanced real-time support, security hardening, hardware enablement.
Current
2004 · Canonical
Ubuntu
Most popular desktop/cloud Linux. Debian-based. Default on AWS, Azure, GCP. LTS releases every 2 years, 5yr support.
1993 · IBM/Red Hat
RHEL / AlmaLinux
Enterprise standard. Subscription-based support. AlmaLinux/Rocky Linux are free downstream alternatives.
1993 · Community
Debian
Foundation for Ubuntu, Raspberry Pi OS, Kali. Pure community governance. Prioritizes stability over recency.
2013 · Offensive Security
Kali Linux
Penetration testing and security research. 600+ pre-installed security tools. Debian-based. Used by security professionals worldwide.
2002 · Community
Arch Linux
Rolling release, minimal base. "Install what you need." Favored by power users and developers for full control.
2003 · Red Hat sponsored
Fedora
Cutting-edge features, upstream-first. Btrfs default since Fedora 33 (2020). Testbed for RHEL features.