Hopefully this tip-toes around the JavaRanch policy effectively.
I would say Sun, IBM and Oracle are all doing a great deal of work with these technologies, as they are pretty much the industry proponents of
JEE. They often release white-papers touting their accomplishments, brilliance, and market dominance over the others, while at the same time, naming other companies with whom they have achieved success.
Probably a quick search on each of these respective companies website would uncover some of these successes, and probably generate a long list of clients.
-Cameron McKenzie
[ June 24, 2008: Message edited by: Cameron Wallace McKenzie ]