RIOT

"RIOT powers the Internet of Things like Linux powers the Internet. RIOT is a free, open source operating system developed by a grassroots community gathering companies, academia, and hobbyists, distributed all around the world.

RIOT implements all relevant open standards supporting an Internet of Things that is connected, secure, durable, and privacy-friendly.

Program like you are used to. Do not waste time with complex or new environments.

• Standard programming in C or C++
• Standard tools such as gcc, gdb, valgrind
• Minimized hardware dependent code
• Zero learning curve for embedded programming
• Code once, run on 8-bit platforms (e.g. Arduino Mega 2560), 16-bit platforms (e.g. MSP430), and on 32-bit platforms (e.g. ARM)
• Partial POSIX compliance. Towards full POSIX compliance.
• Develop under Linux or Mac OS using the native port, deploy on embedded devices.

Benefit from a microkernel architecture and a tickless scheduler on very lightweight devices.

• Robustness & code-footprint flexibility
• Enabling maximum energy-efficiency
• Real-time capability due to ultra-low interrupt latency (~50 clock cycles) and priority-based scheduling
• Multi-threading with ultra-low threading overhead (<25 bytes per thread)

Make your applications ready for the smaller things in the Internet with common system support.

• 6LoWPAN, IPv6, RPL, and UDP
• CoAP and CBOR
• Static and dynamic memory allocation
• High resolution and long-term timers
• Tools and utilities (System shell, SHA-256, Bloom filters, ...)

http://www.riot-os.org/

https://en.wikipedia.org/wiki/RIOT_%28operating_system%29