ChibiOS 3.0 is now composed of several independent but inter-operable sub-projects: RT, NIL, HAL.

ChibiOS 3.0 general highlights

- New files tree organization makes the system more modular.
- A community-contributed code area is now part of the files architecture, it will allow for easier integration of contributed code without much screening.
- Improved startup files, scatter files and build system.
- New licensing options.
- Free ChibiStudio IDE support.

What's new in RT 3.0

- MISRA 2012 compliant.
- Entirely static for enhanced safety.
- System data is now encapsulated in a single "ch" global structure for enhanced safety.
- System integrity check runtime functionality for enhanced safety.
- Tick-less kernel mode helps implement ultra-low-power devices.
- High Resolution Virtual Timers module allows to specify very short intervals.
- High Resolution system time.
- Clock-cycle accurate Time Measurement module.
- Clock-cycle accurate polled delays.
- Statistic module provides high resolution measurement of threads, ISRs and critical zones.
- New recursive locks in addition to the classical critical zone primitives.
- New recursive mode for Mutexes.
- Enhanced suspend/resume mechanism for threads.
- CMSIS-compliant ARM Cortex-Mx port.
- CMSIS RTOS API available.
- Multi-compilers architecture for ports.
- Codebase now compatible with GCC link time optimizations.

What's new in HAL 3.0

- MISRA 2012 compliant.
- HAL is now entirely licensed under Apache 2.0 license.
- HAL has been decoupled from RT. It can now be adapted to any reasonable RTOS or even used with no RTOS at all thanks to a new abstraction layer named OSAL. OSAL implementations are provided for RT, NIL, bare metal ARM Cortex-Mx cores, bare metal Power e200z cores.
- New driver models for ST, I2S, DAC.
- Revamped ADC, ICU, PWM, RTC, SDC, USB drivers.
- Greatly improved STM32 family support, all sub-families have been added.
- Support for new families expanding (Kinetis, Tiva, SPC5xx, RL78, RX62N).
- Streams, channels, files and block devices abstract interfaces.

New addition NIL 1.0

- MISRA 2012 compliant.
- Entirely static for enhanced safety.
- No linked lists anywhere in the code for enhanced safety.
- System data is encapsulated in a single "nil" global structure for enhanced safety.
- Tick-less kernel mode helps implement ultra-low-power devices.
- Ultra compact kernel, well below 1kB in its maximum configuration.
- Upward compatible with RT, it implements a subset of the RT API.
- Reduced RAM usage, 20-28 bytes for task and just 4 bytes for a semaphore on 32 bits architectures, half of that on 8/16 bits architectures.
- ARM Cortex-Mx port based on CMSIS architecture.
- Multi-compilers architecture for ports.