The real-time JRE (RTJRE) provides a highly deterministic Java runtime environment that supports the unique requirements of real-time applications. Each RTJRE is a robust and fully compliant implementation of the Real-time Specification for Java (RTSJ) defined by JSR-1, and includes Apogee developed technologies that provide increased performance and hard real-time responses. In addition, each RTJRE includes the standard Java APIs and features of either MJRE or CJRE.

Each RTJRE includes the target-specific ports of the following components:

• IBM's J9 Virtual Machine (J9VM) extended with Apogee's implementations of RTSJ features that must be supported directly by a Java VM.
  
• Apogee's highly deterministic Just-Ahead-of-Time (JAOT) compiler based on IBM's JIT compiler technology.
  
• Apogee's Real-time Garbage Collector (RTGC) integrated with each port of RT J9VM.
  
• IBM's Foundation Class library (FCL) for the RTJRE based on MJRE.
• Apache's Harmony Class Library (HCL) for the RTJRE based on CJRE.  In this case, the RTJRE also includes a port of Apogee's glue layer of special Java classes and native methods that make the port of HCL work with the port of RT J9VM.
  
• Apogee's Real-time Java Class Library (RTJCL) implementing the RTSJ features that do not have to be supported directly by a Java VM.
  

Support for the following JSR-defined standards is currently under development and will be available when their specifications are completed.

• Safety Critical Java (JSR-302).
  
• RTSJ version 1.1 (JSR-282).

Any optional components, client-side runtimes, and application-level packages available for MJREs or CJREs (please see here) can also be provided with each RTJRE.