The latest Netcraft survey shows that Microsoft’s IIS server is slowly gaining ground on the Apache Web server.  The total number of sites surveyed rose by 2.3 million over last month.  Microsoft’s IIS server gained 2.6 million sites this month while Apache lost 991,000.

Apache has been at the top of Netcraft’s monthly survey since March 1996.  In November 2005 Apache led Microsoft’s IIS with a lead of more than 50 percentage points and a 71% overall market share.  Microsoft has narrowed Apache’s lead down to 16.7% in just two years; if Microsoft continues to grow its market share at the current rate, then it could close the gap on Apache sometime in 2008.

I guess the real question is whether or not it really matters?  Is Microsoft’s IIS less secure than Apache?  Is Apache more efficient?  I’d like to hear people’s opinions on the Apache vs. IIS debate.  Which do you use and why?