WebFX uses GWT to compile your Java code into JavaScript. Normally GWT can only compile the java code (your application logic) and not the JavaFX code (your application UI). WebFX solves this problem by providing a web port of JavaFX (the webfx-kit module) that can be compiled by GWT together with your application code.
WebFX also provides (via the webfx-platform module) some cross-platform APIs (ex: json, timers, websockets, web workers, etc...) that work both in the JVM and the browser.
You will have 2 builds of your application. A pure JavaFX build that you will use for the development, testing and debugging in your preferred Java IDE. And a web build resulting from the compilation of your application code together with the WebFX code by GWT.
The project is still in incubation phase. We are currently building the website, and the next step will be a guide to get you started.
You can't use the project before these steps are completed, but don't hesitate to star the repository to let us know you are potentially interested in this technology for your future projects.
Your questions and comments are also very welcome in this discussion thread.