Java plug-in wish list: JVM scope
One thing in particular, though, I think is needed: JVM applet scope. That is: the ability to run a set of applets in the same JVM, controlling which ones go together. The two real cases that I would need are "page" (all applets in the page scope on the same page instance share the same JVM) and "application" (all applets in different pages that declare to be in the same application share the same JVM).
The first is really to have different applets that can interact with each other, and it would actually go together with the ability to drag applets out. You can imagine two applets, one that is essentially a display of some data, and the other with the parameters for the display. You set your display the way you want, and when you are done you drag the display out and close the page.
The second would be used to share data cache. I have multiple pages that work on the same big dataset, and I would like different pages to simply use the same cache.