These notes are for Java developers who want to convert their Java applets or Java applications to JavaScript. Developers of java2script/SwingJS itself should read README-developers.md .
java2script/SwingJS includes an Eclipse plug-in (technically a "drop-in"), net.sf.j2s.core.zip, along with a JavaScript version of the Java Virtual Machine (SwingJS) to allow the rapid and automated production of browser-ready JavaScript versions of Java applications and applets.
See https://github.com/BobHanson/java2script/tree/master/dist