It was made with the intention of replacing Swing. Java Fx is used to make Desktop application and Rich Internet Applications (RIAs).
* Software platform * Desktop application * Rich internet applications(RIAs) * Standard GUI * Support for desktop computers,web browser,microsoft windows,linux and mac operating system.
JavaFX is a software platform for creating and delivering desktop applications, as well as rich internet applications (RIAs) that can run across a wide variety of devices. JavaFX is intended to replace Swing as the standard GUI library for Java SE, but both will be included for the foreseeable future.
http://docs.oracle.com/javafx/2/overview/jfxpub-overview.htm