Microsoft Opens Its Azure RTOS, Spins the Project Out Under an Open License as Eclipse ThreadX

Microsoft has announced that it is making Azure RTOS, its embedded development suite built around the ThreadX real-time operating system, open source — donating it to the Eclipse Foundation where it will be known as Eclipse ThreadX.

"Reinforcing our commitment to innovation and community collaboration, Azure RTOS will be transitioning to an open source model under the stewardship of the Eclipse Foundation, a recognized leader in hosting open source IoT [Internet of Things] projects," Microsoft's Stefan Wick explains of the move. "With Eclipse Foundation as the new home, Azure RTOS becomes Eclipse ThreadX – a comprehensive embedded development suite including a small but powerful real-time operating system that provides reliable, ultra-fast performance for resource-constrained devices."

The ThreadX real-time operating system (RTOS) was launched in 1997 by William Lamie, president and chief executive of Express Logic — a company which Microsoft acquired in 2019. Post-acquisition the platform became known as Azure RTOS ThreadX and then just Azure RTOS, offering a full development suite designed for embedded devices. Now, it will be under the auspice of the Eclipse Foundation — and fully open source for the first time, while retaining its functional safety and security certifications.

"By publishing Eclipse ThreadX as an open source project, we are placing it at the heart of a vibrant ecosystem led by the Eclipse Foundation and our industry leading partners," Wick claims. "The deep expertise in technology, combined with the collaborative spirit of the global developer community, holds vast potential for Eclipse ThreadX to evolve, innovate, and continue shaping the IoT landscape in exciting ways."

"This new project is exactly what the highly fragmented embedded software market has needed for a very long time," claims Eclipse Foundation executive director Mike Milinkovich of the opening. "Eclipse ThreadX presents the industry with a game-changing opportunity. Having a performant, mature, safety and security certified, permissively-licensed, open source RTOS under vendor-neutral governance will enable new business and product opportunities around the world. We are very excited to work with the community to make ThreadX a huge success."

The Eclipse Foundation has formed an interest group which will seek sustainable funding for the project, and has already named AMD, Cypherbridge, Microsoft, NXP, PX5, Renesas, STMicroelectronics, Silicon Labs, and Witekio (an Avnet company) as early supporters. The move also covers ThreadX's sub-components, including the FileX fault-tolerant file system, USBX, NetX Duo, and graphical user interface runtime GUIX, all of which will join the core ThreadX RTOS at the Eclipse Foundation.

It will take a little time before Eclipse ThreadX is ready for release, however. "The intent is to have the first release of ThreadX under Eclipse Foundation governance completed by the end of January 2024," Milinkovich says, while the Foundation has confirmed that the code will be provided under the permissive MIT license to make adoption "as simple as possible for all parties" — a shift from its current "source available" status under a custom and considerably more restrictive Microsoft software license.

More information is available on the Eclipse ThreadX website.