Agreed. If you're new to this stuff:
The basic gist being that, lucky for us, Infocom made their games easy to port between systems by using a "virtual machine." Their games consist of a data file, universal to all operating systems; and an interpreter, particular to each operating system. Buy any version of Infocom games and as long as you can read the disk/CD, you can pull off the data files. Then you just use an interpreter specific to your platform (like Zoom for OS X, or WinFrotz for Windows) to play the game!