Scott Rosenberg makes a good and obvious point about software today — it decays. In response to an economic argument that software does not decay in the same way that manufactured goods do, he points out that installations of software do become more and more iffy over time. Beyond that, hardware marches on, as does other software. You can grab Netscape 3 from Evolt and run it, but will it really work very well on a new computer running Windows XP? Or you can run Firefox on Windows 98, but will you be able to use that USB 2 DVD burner that you’ve been wanting? And how about that new Bluetooth phone you have? Will you be able to share data with your desktop apps? These considerations are less important when it comes to large business applications, but they’re still there. Generally there’s enough money involved that you can write adapters to tie your old applications to the latest and greatest front end rather than migrating to something new, but isn’t that true in industry as well? I doubt that automotive factories or power plants upgrade all of their machinery very often. New factories or plants get built with the latest technology (just like new applications) but the old installations go on in maintenance mode forever.