+ NppExec is an intermediary between Notepad++ and external tool/compiler. It allows to run external tool/compiler directly from Notepad++.
+ NppExec is a Console window which can show the running process'es output, and can redirect the Console window's input to the running process (with some limitations).
+ NppExec is an interpreter of its own internal commands. NppExec can execute several commands one after another (so-called NppExec's script) from its "Execute..." dialog and can execute single command directly from its Console window.