Before installing Kawa, you will need a working Java system. The released Kawa jar file assumes Java 8 or newer. You need to build Kawa from source if you have Java 5, Java 6, or are targeting Android. (Older versions of Kawa have been reported to work with JDK from 1.1, Kaffe, Symantec Cafe, J++, and GCJ, but these are no longer supported.)

The discussion below assumes you are using the Java Developer’s Kit (JDK) from Oracle. You can download free copies of JDK 8 for various platforms.

The program java is the Java interpreter. The program javac is the Java compiler, and is needed if you want to compile the source release yourself. Both programs must be in your PATH. If you have the JDK in directory $JAVA_HOME, and you are using a Bourne-shell compatible shell (/bin/sh, ksh, bash, and some others) you can set PATH thus:

PATH=$JAVA_HOME/bin:$PATH
export PATH