Harmony Class Library (HCL) from Apache Foundation provides class library for CJRE.  Apogee continually tracks and integrates latest changes from the Apache, while fixing and contributing back relevant changes.  CJRE can currently be configured to use 'Java 5' (J2SE 1.5-compatible) or 'Java 6' (Java SE 6-compatible) Harmony branch.

Harmony provides a number of advantages, including:

• open source, licensed under Apache License
  
• active development and support by both individual and commercial entities
  
• 99%+ completeness when compared with Sun's J2SE
  
• modular design, allowing for distribution of only utilized java packages

Apogee has implemented a number of improvements targeting embedded systems, such as:

• ports to multiple operatings systems and architectures
• support for minimizing runtime footprint using SmartLinker tool
• support for AWT/Swing/Java2D using GDI on Windows CE/Mobile targets
• support for AWT/Swing/Java2D using DirectFB on Linux targets
  

Harmony support (if implemented) is enabled via -jcl:harmony option.