Mac

Mac 64 bit, Mavericks onwards.   Version 1.0.2
Instructions: Open the DMG by double clicking on it. Drag Print42 into Applications. 

Download for Mac

Windows

Windows 10 64 bit. Latest version of Windows as of 2018. It may work with earlier versions of windows.
Version 1.0.2

Instructions: Run the setup executable.

Download for Windows

Drivers?

Print42 comes with its own driver (auto installed, so you don't need to worry).
Print42 co-exists happily with the normal Epson drivers for your Epson thermal printer.  For a list of Epson thermal printer driver downloads click here
Only registered versions actually print to a thermal printer.

You don't need to worry about drivers or hardware at all if you want to simply use Print42's free mode.
Print42 can print selections of tape to normal desktop printers, if you wish. This is free - but you want to buy a thermal printer to experience the coolness of line by line printing :-)

Note: Unregistered versions of Print42 will attempt to print a couple of lines to a thermal printer, allowing you to test any thermal printers you may already own, before purchasing a license.