Mr. Mepis — A brother who has instructions for installing Watchtower Library onto a computer using Linux as the operating system.  This involves using the WINE add-on to Linux which runs Windows based software.    The brother says it is not too much trouble and is worth the effort if you want to move away from the Windows environment.    Not tested, but the site looks professional with enough information for most computers users with some skills.   Perhaps not for the non-technical users, though.