What is the Real-Time Specification for Java?

Bill Day

Real-Time for Java (RTJ) specifies additions and updates to standard Java Virtual Machines, language, and API features to support real-time programming using Java technology.

RTJ is constructed so that one can provide real-time support for the full Java 2 Platform (J2SE/J2EE) as well as for PersonalJava, EmbeddedJava, and CLDC/KVM-based devices so long as the devices have a Real Time Operating System (RTOS) which supports certain requirements called out in the RTJ specs.

The RTJ expert group was charted as the first Java Specification Request (JSR) operating under the Java Community Process. IBM made the original proposal and acts as the specification lead. (Sun is a participant like all of the other expert group companies, though Sun's rep does happen to be James Gosling.) Read the original JSR at:

The latest information on the specification, including information on the expert group members and links to download the specification in PDF format, are available from the Real Time Java site: