Download eclipse-build (source code can be found here) and run the following command:

java -jar eclipse-build.jar --config https://raw.githubusercontent.com/specs-feup/kadabra/master/JavaWeaver/eclipse.build

This should create the file JavaWeaver.jar.

A zip file with a precompiled Kadabra JAR can be downloaded from this link.

There is a demo online version of Kadabra available here.

Please check the README file in repository specs-java-libs.