* Preemptive scheduler with 255 priority levels * Round-robin at same priority level * Lightweight: the entire operating system fits into a few C files * Highly portable ANSI C code not tied to any compiler * Easy to read, well-documented, doxygen-commented code * Can be ported to any CPU architecture with a single architecture-specific module * Automated test suite proves reliable kernel operation * Free and flexible open source, BSD-licensed code * Readable code provides a good platform for learning RTOS internals

* Free RTOS scheduler - preemptive, cooperative and hybrid configuration options, with optional time slicing. * The SafeRTOS derivative product provides a high level of confidence in the code integrity. Includes a tickless mode for low power applications. * Tiny footprint. * Official support for >30 embedded system architectures (counting ARM7 and ARM Cortex-M3 as one architecture each). * FreeRTOS-MPU supports the ARM Cortex-M3 Memory Protection Unit (MPU). * Designed to be small, simple and easy to use. Typically a RTOS kernel binary image will be in the region of 4K to 9K bytes. * Very portable source code structure, predominantly written in C. * Supports both real time tasks and co-routines. * Direct to task notifications, queues, binary semaphores, counting semaphores, recursive semaphores and mutexes for communication and synchronisation between tasks, or between real time tasks and interrupts. Innovative event group (or event flag) implementation. * Mutexes with priority inheritance. * Efficient software timers. * Powerful execution trace functionality. * Stack overflow detection options. * Pre-configured RTOS demo applications for selected single board computers allowing 'out of the box' operation and fast learning curve. * Free monitored forum support, or optional commercial support and licensing. * No software restriction on the number of real time tasks that can be created. * No software restriction on the number of task priorities that can be used. * No restrictions imposed on task priority assignment - more than one real time task can be assigned the same priority. * Free development tools for many supported architectures. * Free embedded software source code. * Royalty free. * Cross development from a standard Windows host.