Mariusz, just a few comments as I've laid out my opinion in another post - that I've been busy writing when your article arrived.
All of your examples could be resolved by a WorkOn task or something like that, which would be a subclass of Exec that implements MatchingTaskBehavior. I don't know whether we'd use different subclasses for "all files at once" and "one file at a time" or use a flag for this - I'd opt for the latter. Stefan
