The easiest way to start up Kawa is to run the ‘kawa’ program. This finds your Java interpreter, and sets up ‘CLASSPATH’ correctly. If you have installed Kawa such that $PREFIX/bin is in your $PATH, just do:

kawa

However, ‘kawa’ only works if you have a Unix-like environment. On some platforms, ‘kawa’ is a program that uses the GNU ‘readline’ library to provide input line editing.

To run Kawa manually, you must start a Java Virtual Machine. How you do this depends on the Java implementation. For Oracle’s JDK, and some other implementations, you must have the Java evaluator (usually named java) in your PATH. You must also make sure that the kawa/repl.class file, the rest of the Kawa packages, and the standard Java packages can be found by searching CLASSPATH. See Running Java.

Then you do:

java kawa.repl

In either case, you will then get the ‘#|kawa:1|#’ prompt, which means you are in the Kawa read-eval-print-loop. If you type a Scheme expression, Kawa will evaluate it. Kawa will then print the result (if there is a non-"void" result).