LJRT - Lund Java based Real-Time


The LJRT has, until now, only been run on hosts running GNU/Linux or Solaris. There should be no problems running on anything that looks like unix (MacOS X, *BSD, etc.) but it has not been tested by us. Running on Windows is a different story, either use cygwin to get a unix-like environment or reconstruct the build system in an IDE should be possible.


The easiest way of getting started using the LJRT system is to download the latest version of the jar package, and install it issuing the command:

java -jar ljrt-<version>.jar

Latest Version


Older Versions


Source Code

If you are interested in modifying, or just look at, the compiler source code, you can instead download the latest source code package and untar in a suitable location. From there on it works exactly as the "binary" package, with the difference that all source code is present so that you can modify and rebuild the compiler.




Reference manual

Reporting bugs

The LJRT project is a research prototype, and not yet of product quality. There are many (undocumented) bugs and rough edges which have a nasty habit of slapping ones face once in a while. We are very grateful if you would like to submit as detailed bug reports and feature requests as possible.

Our Bugzilla is a very good place for posting bug reports and feature requests.

LJRT library

The real-time classes are also available in a 100% Java version to be used when running in a JVM during application development. Timing will of course not be hard real-time, but concurrency characteristics will be the same as when the application is cross-compiled and run on the target system with a RTOS.

You can also browse the LJRT API online documentation.

Note: The term Java-based that is due to the fact that our way to accomplish a J2SE-compatible (any embedded program will for sure run on any Java-enabled desktop, which is more standard Java than J2ME or a RTSJ will provide) is not compatible with the Java license conditions from Sun (we provide a real-time improved J2SE subset affecting the RTOS API without going via the JCP and without requiring a JVM). Thus, we may not call our free solution "Java", so we call it Java-based (again, this is legally not Java).

© Lund Institute of Technology 2006. Anders Nilsson.

Last update: Sunday, 12-Mar-2006 23:00:20 CET