I've been coding for a few decades. My favorite language is Delphi. DIA4 is written in Delphi, which is probably why the false positive on the antivirus software, but DIA4 is clean. DIA versions 1, 2, and 3 were 16 bit character based apps. DIA4 is 32 bit, handles long file names, etc.
Over the years, I noticed that I repeatedly did lots of "Explorer" kinds of things, but kept starting and stopping a collection of programs in order to "get the job done". As a programmer, I needed power and flexibility and speed. I developed DIA, Does-It-All, long before Explorer, and long before object oriented programming. The concept is that you view the files in a folder and you can take actions on a file in that folder. DIA4 is a "keyboard friendly" application: you leave the mouse alone and keep your fingers on the keyboard. It's faster than explorer once you get used to it. It can call your favorite text editor. The text file utilities are powerful and can handle huge files.
I've attached screenshots of the program and the (built-in) Help screen.