Maybe that's an indication that the configuration of the web server should be partitioned into "basic configuration" (which they can all support) and a few othe

Maybe that's an indication that the configuration of the web server should be partitioned into "basic configuration" (which they can all support) and a few other categories (which are supported by a subset), i.e. the configuration itself should be "standardized". I realize that this is a nontrivial proposition, but if we're ever going to realize the dream of "interchangeable parts" we're going to have to learn to do this stuff.