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

February 09, 2011

The RTEMS Project is pleased to release 4.10.0. This is the first release from the 4.10 release series and is primarily a...

January 07, 2011

The RTEMS Wiki has been upgraded to the latest version of Mediawiki. In addition, the Semantic Wiki extensions have been installed. This extensions...

December 01, 2010

Joel Sherrill will be speaking Thursday, December 9, 2010 at the Flight Software Workshop at the California Institute of Technology in Pasadena, CA. I will also be participating in a panel discussion that evening. This event is hosted by The...

October 28, 2010

The GangOctober 22, 2010 is a date which will long be remembered. Chris Johns, Ralf Corsepius, and I were in...

October 20, 2010

I have run David Wheeler's sloccount on RTEMS and written the results up in a blog entry.

There are more details in the blog but highlights are that...

August 25, 2010

Thanks to the success of Vinu Rajashekhar's Google Summer of Code project, we are pleased to announce that there is now support for the Go programming language, a new systems language, for RTEMS. Vinu successfully...

August 22, 2010

I updated Drupal and Mediawiki this morning on the server to the latest and greatest version. This is a largely manual operation and although everything appears to be fine, I wanted to let everyone know something changed. So if you see an anomaly, please report it.

July 03, 2010

As June ends, it has been a month since the end of the bonding period. In this report, we find out what the students and mentors have accomplished in that time. Personally, I am impressed with the progress they have made. I encourage the community to communicate with and challenge the...

June 17, 2010

Today marks a new phase in the life of RTEMS, as we introduce the first 64-bit processor family, the SPARC V9 (sparc64). Gedare Bloom (GSOC 2010 student) and Eugen Leontie (husband of GSOC 2009 student) have worked diligently to port RTEMS to the SPARC V9 CPU and have provided two BSPs that...

June 16, 2010

Sometimes we don't realize how much time has passed since we last worked on something. In this case it was viewcvs.cgi. Chris Johns reported that it was crashing under certain conditions. A quick review said that we had a version dated 1999. It apparently served us well and quietly for 11...