It's Windows software, Open Source is less common over there. If you want OSS alternatives for Linux, here are some. A few may look old and unpolished, but today pretty much every desktop environment comes with its own file manager.

https://www.4pane.co.uk/

https://doublecmd.sourceforge.io/

https://ignorantguru.github.io/spacefm/

http://tuxcmd.sourceforge.net/

http://www.boomerangsworld.de/cms/worker/

http://roland65.free.fr/xfe/