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

November 09, 2011

Chris Johns recently made an announcement to the RTEMS Users mailing list which gave the status of the CVS to Git conversion process. Read that email for details and watch the Users' List for follow ups. Feel free to...

November 04, 2011

Presentations from the 2011 Workshop on Spacecraft Flight Software are now available online at http://flightsoftware.jhuapl.edu/.

The presentations were interesting and I hope you take the time to...

October 14, 2011

This was an interesting year for the RTEMS Project and the Google Summer of Code. We had eight wonderful students who challenged each of the mentors to do their best. I hope that we can keep them all involved with RTEMS in some capacity. They were all very good and highly productive. If...

October 14, 2011

The RTEMS Project will be making an appearance at the Flight Software Workshop to be held at The Johns Hopkins University Applied Physics Laboratory from October 19 - 21, 2011. Joel Sherrill will be presenting an updated version of the RTEMS...

July 25, 2011

The RTEMS Project provides support for two branches, currently 4.10 and 4.9, as well as the development head (e.g. 4.11). OAR Corporation recognizes that a project may select an RTEMS version and choose not to upgrade to new release series. This minimizes the impact of tool updates and RTEMS...

July 24, 2011

The RTEMS Project is pleased to release 4.9.6. This is the seocnd release from the 4.9 release series and includes both bug...

July 24, 2011

The RTEMS Project is pleased to release 4.10.1. This is the second release from the 4.10 release series and includes both...

July 19, 2011

The participating organizations in the first http://sophia.estec.esa.int/socis2011/ has been announced. There are 32 participating organization and each is to be allowed one student.

From the announcement:

For the first...

July 15, 2011

DAWN was launched September 2007 and has taken almost four years to reach its first science stop. It is to enter the orbit of the asteroid Vesta today (15 July 2011) and orbit for...

May 19, 2011

Dr James Johannes passed away earlier this week. He founded On-Line Applications Research (OAR) Corporation in 1978. He was an Emeritus Professor of the Computer Science department faculty at...