Apache for Mac OS X:: httpd.conf for Mac OS X Server 10.x
Mac OS X Server 10.x uses the GUI control panel interface called ServerAdmin to administer services. It’s something like apache.conf, linux.conf, bind.conf, and other services put into one place.
When you use ServerAdmin to setup your web server, it writes to a file called httpd_macosxserver.conf. This is a seperate file from the usual httpd.conf and is called by httpd.conf by use of the Include directive.
httpd_macosxserver.conf overrides almost every directive set in httpd.conf, and has some other Mac OS X tweaks not included in the original httpd.conf.
httpd_macosxserver.conf warns in its comments area that you should not edit anything by hand – everytime you use the ServerAdmin GUI, it will be overwritten and lost. So, what do you do if the GUI doesn’t give you enough power and you NEED to edit the conf files by hand?
Why, you just put another Include directive in httpd.conf.
Because httpd.conf is not overwritten by ServerAdmin, you do not have to worry about losing the Include directive, and you will be editing your own conf files safely tucked away somewhere else under your username so that future updates to Apache will not overwrite them.