mbed OS now incorporates an RTOS in the core of the operating system, which can be summarised into the following enhancements:
- Native thread support to the OS and applications
- Simplifications of the networking stacks and components integration
- Enabling blocking and non-blocking execution mechanisms
- Reduced overhead required by the RTOS
- Event-driven model can be integrated into threads as libraries
This integration brings together the original mbed OS 2 and mbed OS 3 codelines, re-basing and merging the two development lines into one platform. It is worth mentioning that mbed already contained an RTOS, which was/is based on RTX implementation of CMSIS. However, the integration of CMSIS, peripherals and user code was too complex.
More information can be found on mbed website.