DiscoBSD is a 2.11BSD-based UNIX-like operating system for microcontrollers, with a focus on high portability to memory constrained devices without a memory management unit.

This microcontroller-focused operating system is the continuation of RetroBSD, a 2.11BSD-based OS targeting only the MIPS-based PIC32MX7. DiscoBSD is multi-platform, as it also supports Arm Cortex-M4 STM32F4 devices.