Software Lifespan

Last weekend a friend of mine told me an interesting story. Some software on a build server had stopped working unexpectedly. It turned out the software in question expired after 10 years! Yep, you read it right. On top of this as it turned out the company that made the software does not exist anymore. It took 5 days for the company my friend work for to find a contact of the author of the software. Fortunately the solution was easy – they had to uninstall the software, delete a “secret” key in the registry and then install the software again.

This story reveals some interesting things:
1) a software written in 2002 is still in use today
2) the way we do differentiate between a trial and a non-trial software

We all know the mantra that we do not have to make assumption how long our software will be in use. Out of curiosity I asked my friend how it happens to have a build machine that is 10 years old. It turned out it was a Windows XP machine that was migrated to a virtual server many years ago. Interesting, don’t you think? The hardware lifespan is much shorter than the software lifespan.

For comparison, Windows XP was released in 2001 but it doesn’t expire as the software in question. I can easily imagine how the particular expiration check is implemented. During the installation it takes the current date and if a valid serial key is entered it adds 10 years, otherwise it adds, say, 14 days. The interesting thing is the idea that the software won’t be used after 10 years. Back then, I would probably implement that expiration check in a similar way. In the best case I would probably add 20 instead of 10 years. I remember those days very well; all the dynamics and expectations after the dot-com bubble. My point is that for the small software vendors a 10 years period was equal to eternity. For companies like Microsoft a 10 years period is just another good step (at the time of writing different sources estimate that Windows XP has between 22% and 35% of the OS market share).