Releases and Active Development
  • The current release is 5.3 (download here). Note that this release branch was planned to be 4.12 but significant changes warranted bumping the major number (e.g. 4 to 5). The new release numbering scheme is described here.
  • The previous release series was 4.11 and the last release from that branch is 4.11.3 (download here).
  • The next release branch is planned to be 6. For details and status, visit the Release page. This is the git master.
  • Information on older releases is available here.

What is RTEMS?

The Real-Time Executive for Multiprocessor Systems or RTEMS is an open source Real Time Operating System (RTOS) that supports open standard application programming interfaces (API) such as POSIX. It is used in space flight, medical, networking and many more embedded devices. RTEMS currently supports 18 processor architectures and approximately 200 BSPs. These include ARM, PowerPC, Intel, SPARC, RISC-V, MIPS, and more. RTEMS includes multiple file systems, symmetric multiprocessing (SMP), embedded shell, and dynamic loading as well as a high-performance, full-featured IPV4/IPV6 TCP/IP stack from FreeBSD which also provides RTEMS with USB.

Major decisions about RTEMS are made by the core developers in concert with the user community, guided by the Mission Statement. We provide access to our development sources via a Git Repository (see these Instructions for details). We strive to provide regular, high-quality releases, which we want to work well on a wide range of embedded targets using cross development from a variety of hosts including GNU/Linux distributions, MS Windows, BSDs, Solaris, and Mac OS. We encourage everyone to contribute changes and feedback to RTEMS.

Commercial support is available from US and European companies, and free support comes via the active global community.

RTEMS News

September 02, 2014

The RTEMS Project finished another year of Google Summer of Code, with five students successfully completing projects from various areas of RTEMS. The final report with specific project details from each student can be found here for html...

May 06, 2014

RTEMS is fortunate enough to be included once again in the ESA Summer of Code in Space. We want students!

This year we want to encourage the SOCIS students to focus on improvements to our new rtems-test Python-based framework. This will...

April 29, 2014

Last week the two Google Code-In 2013 Grand Prize Winners from RTEMS went to Google for the Grand Prize trip. This year RTEMS was allowed to send one mentor, so Gedare accompanied the two winning students. The trip was a lot of fun, and we look forward to GCI 2014!

February 07, 2014

Our friends at embedded brains GmbH will have a booth at the Embedded World 2014 Exhibition and Conference in Nuremberg, Germany. The conference is open from February 25 'til February 27. See the Embedded World ...

January 31, 2014

Thanks to Ben Gras from Minix, Joel Sherrill gave a talk about RTEMS at VU University in Amsterdam!

Title: Scheduling and Thread management with RTEMS
Hosted by: Herbert Bos and Ben Gras
When: Tuesday, January 21, 2014
Where: Mathematics and Science Building ("Wiskunde...

January 23, 2014

Between mid-November and early January, the RTEMS Project participated as one of ten mentoring organizations in the Google Code-In (GCI), a contest for pre-university students that encourages the involvement of...

December 05, 2013

For many years RTEMS.ORG and RTEMS.COM have pointed to the same IP, same services, and same content. However, very soon the RTEMS.ORG and RTEMS.COM domains will be separated to cover their own unique content.

The RTEMS Community will continue to operate under the RTEMS.ORG site. The...

October 11, 2013

The RTEMS Project had another great Google Summer of Code! Eight students successfully completed projects spanning the range of RTEMS. Good news from each of the students, in their own words, is included in the...

April 08, 2013

The RTEMS Project has been accepted as a participating organization in the Google Summer of Code 2013. We have been busy in the off-season getting ready for potential students. Visit the updated...

February 15, 2013

I (Joel) gave two brief presentations today at the University of Tennessee at Chattanooga on RTEMS and Google Summer of Code 2013. I shared my experiences in a blog post. PDFs are available as part...