I must be honest, I believe that the Apache web server and Open-source technologies such as Linux, PHP and MySQL (a bundle known as LAMP) will, most likely, always possess the largest market share of the web server market. The constituency of LAMP admins/users/developers consists of high numbers and unparallelled loyalty, but a recent blog entry on TechRepublic cited a recent survey that indicates the LAMP market share is losing ground significantly to Microsoft IIS.

I have been developing ASP Classic/ASP.NET applications on the IIS platform for 6 years now. I started with IIS5 on Win2K server. The product was good, but the advancements made in the last few years that embrace the .NET Framework have truly been amazing. ASP.NET, now in version 2.0, has taken web development to a level that I would have never imagined possible. It is no wonder that some open source guys (including MIT, where open source was born) are making statements like this:

ASP.NET 2.0 is a much more viable platform for sophisticated apps than it used to be. MIT recently switched from java to C# for 1st year developers and I see .NET as much as J2EE in app jobs. As well, when I go to more sophisticated sites there are alot more .aspx is the URLs these days.

It's taken a number of years for this to happen, but through a few versions of the technology, the .NET Framework it is gaining a level of sophistication and maturity that developers can no longer deny. The fact that the underlying platform is built to run hand-in-hand with IIS is most likely the largest cause for this recent change of market share in the web server market.