[jasonjayr]

Windows commander (As it was called back then) was the first piece of shareware I've ever registered, back in the 16-bit Windows 3.1 days, which is just as long as I've been using it as well :)

Impressively, it is still under active development.

"Double Commander" is a very complete open source re-implementation in QT, and they are targeting all 3 major platforms with it. There are a few quirks that will be noticeable for anyone that's nimble with Total Commander, but the keybindings and even the menus are just about the same, and if that's what's keeping you on Windows -- the benefit of the linux ecosystem will greatly outweigh those small nuisances.