Other JDKs
In addition to the most widely used JDK discussed in this article, there are other JDKs commonly available for a variety of platforms, some of which started from the Sun JDK source and some which did not. All of them adhere to the basic Java specifications, but they often differ in explicitly unspecified areas, such as garbage collection, compilation strategies, and optimization techniques. They include:
In development or in maintenance mode:
- OpenJDK;
- Aicas JamaicaVM;
- GNU's GCJ (The GNU Compiler for Java);
- IBM J9 JDK, for AIX, Linux, Windows, MVS, OS/400, Pocket PC, z/OS;
- Oracle Corporation's JRockit JDK, for Windows, Linux, and Solaris;
- RedHat IcedTea, replacing the proprietary classpath in OpenJDK.
Not being maintained or discontinued:
- Apache Harmony
- Apple's Mac OS Runtime for Java JVM/JDK for Classic Mac OS
- Blackdown Java – Port of Sun's JDK for Linux
Read more about this topic: Java Development Kit