μClinux is a variation of the Linux kernel, previously maintained as a fork, that targets microcontrollers without a memory management unit (MMU).

[1] It was integrated into the mainline kernel as of 2.5.46;[2] the project continues to develop patches and tools for microcontrollers.

Initially, they targeted the Motorola DragonBall family of embedded 68k processors (specifically the 68EZ328 series used in the 3Com PalmPilot) on a 2.0.33 Linux kernel.

μClinux had support for many architectures, and forms the basis of many products, like network routers, security cameras, DVD or MP3 players, VoIP phone or gateways, scanners, and card readers.

[5] The obsolete CPU architectures set to be removed in Linux 4.17 and subsequent releases included ADI Blackfin, Etrax CRIS, Fujitsu FR-V, Mitsubishi M32R, Matsushita/Panasonic MN10300, Imagination META (Metag), and Tilera TILE.