XnView Software

In Categories Filter after selecting at least one category, highlight those that have common items with current (or grey out those that do not have). Or simply show a number of common files in brackets (instead of the current brackets representing how much every category contains files). Or add ...

+1 it would be so useful when using regular expressions. But also show subcategories (or option for it) or grey out those what do not match search and aren't subcategories.
Because for search, among Action s, now we have only Open Tree .

Also, very well done with XnViewMP's categorization, but ...