Allows you to insert Java applets into your WordPress blog.
Loading a Java applet takes time, especially the first time the Java plug-in is loaded by the browser and especially the first time the JAR file is downloaded by the browser. Your users may be annoyed if your page immediately does all this without their initial confirmation and causes delays.
It's very likely to work for other versions of WordPress, so give it a shot, and let me know how it works out.
Right now, that's not supported. Only JAR files can be uploaded to WordPress. You have to place your supporting files somewhere else: outside of the management of WordPress or some other web site. If there's enough user demand, I'll look into supporting more file types for upload.
Not right now. I don't know if there's demand for it.