There are certain milestones in the life of a product when developers are free to ask if it’s time to change the platform it’s developed on. Typically you’ve shipped a major version and gone into maintenance mode. Planning has started for the next version, and you wonder if you should stick with what you’ve got or if, knowing what you know now, it might be better to switch from .NET to PHP, or from PHP to Java.
You might think that checking Netcraft would be a good idea. You can see if your current platform is gaining or losing market share, and who doesn’t like market share? If you look at the latest chart you’ll see that Microsoft is gaining on Apache.
But keep in mind that while Apache’s market share has gone down marginally, the total number of sites has still gone up. Most of Microsoft’s gain is from new sites, not from existing sites switching. (The exception being large site-parking operations switching to IIS.)
But really the important question is whether your preferred platform faces a reasonable possibility of becoming obsolete/unsupported. This is actually one place where the Unix world’s slower upgrade cycles help. You rarely have applications “sunsetted” by the manufacturer.
Am I arguing in favor of dropping .NET? Not at all. I think you should use what works for you. What I’m saying is unless your chosen platform is in danger of becoming unsupported, and that causes a problem for you, then looking at market share charts should never get you to switch.
Now if you hadn’t already chosen a platform, and you wanted to know what platform had a larger market, then you’d care about market share. But that’s a subject for another post.