Java - The Bare JDK. Java has been supported by the blackdown port of the JDK (Java Development Kit) of Sun to the Linux platform. It used to lag behind Sun's JDK versions - it doesn't lag now. The JDK contains javac (a java source to by code compiler), jdb (a very primitive debugger), jar (JAR files manager), etc. The JDK is the Java-equivalent of the GCC tools family. Because Java is portable, its possible to develop on a Linux platform, and later deploy the code on other platforms, so Linux for Java development makes perfect sense.