FreeMind is above all a Java application or program. In addition to that, there is also FreeMind applet, one that makes is possible to serve FreeMind mind maps from a web server to a web browser, mind maps that are stored on the same web server as the applet. The FreeMind applet runs in what is known as browse mode. The applet does not make it possible to edit mind maps on the web server, only to view them.
In FreeMind 0.9.0, there is an export function that exports a mind map bundled with the applet. It is in menu File > Export > As Java Applet.
Guides on FreeMind applet: