μC/OS-II is a portable, ROMable, scalable, preemptive, real-time deterministic multitasking kernel for microprocessors, microcontrollers and DSPs.


  • Preemptive multitasking real-time kernel with optional round robin scheduling
  • Delivered with complete, clean, consistent source code with in-depth documentation.
  • Highly scalable: Unlimited number of tasks, priorities and kernel objects
  • Resource-efficient: 6K to 24K bytes code space, 1K+ bytes data space)
  • Very low interrupt disable time
  • Extensive performance measurement metrics (configurable)
  • Certifiable for safety-critical applications

Website: https://doc.micrium.com/display/ucos/

Source code: https://github.com/SiliconLabs/uC-OS2

License: Apache License 2.0

uC/OS-II Platforms

  • ARM
  • ColdFire
  • AVR
  • AVR32
  • 80X86
  • PowerPC
  • RISC-V
  • MSP430
  • PIC32

uC/OS-II Components

  • FileSystem
  • Network
  • USBHost
  • USBDevice
  • Modbus
  • GUI
  • CAN