It was developed by William Lamie,[4] who was also the original author of Nucleus and PX5 RTOS, and was President and CEO of Express Logic.
On April 18, 2019, Microsoft purchased Express Logic for an undisclosed sum and it was renamed to Azure RTOS.
[2] On November 21, 2023, Microsoft announced Azure RTOS would be transitioning to an open source model under the stewardship of the Eclipse Foundation, and making the project available under the permissive MIT License.
ThreadX provides priority-based, preemptive scheduling, fast interrupt response, memory management, interthread communication, mutual exclusion, event notification, and thread synchronization features.
Major distinguishing technology characteristics of ThreadX include preemption-threshold, priority inheritance, efficient timer management, fast software timers, picokernel design, event-chaining, and small size: minimal size on an ARM architecture processor is about 2 KB.
[6] ThreadX implements a priority-based, preemptive scheduling algorithm with a proprietary feature called preemption-threshold.
The latter has been shown to provide greater granularity within critical sections, reduce context switches, and has been the subject of academic research on guaranteeing scheduling.
[9] As of 2017, ThreadX is packaged as part of X-Ware IoT Platform in full source code and with no runtime royalty payment.
It provides a 2D computer graphics system that supports multiple display devices with a variety of screen resolutions and color depths.
Optional protocols include ARP, Auto IP, DHCP, DNS, DNS-SD, FTP, HTTP, ICMP, IGMP, mDNS, POP3, PPP, PPPoE, RARP, TFTP, SNTP, SMTP, SNMP, and Telnet.
It supports these USB Device Classes: Audio, Asix, CDC/ACM, CDC/ECM, DFU, GSER, HID, PIMA, Printer, Prolific, RNDIS, and Storage.