PI has File>Close All. It would be useful to also have File>Close All Except Selected .
Often I find that after playing with something like ImageIntegration I finally get a file that I want to keep and continue working with, plus a whole lot of other unwanted files. I either have to close (one-by-one) the files I don't want, or else save the desired file, close all, then reopen the wanted file.
Geoff