What did the majority of websites use as web server, before Apache in 1995?
The Apache About page describes it all: http://httpd.apache.org/ABOUT_APACHE.html
There was a product called "NCSA httpd" which was in general use before Apache came about. It didn't take long for Apache to pass httpd up as the #1 deployed web-server. The curve can be found in the NetCraft web-surveys (link).
Well, apache was a patchy webserver - a set of patches to the NCSA httpd webserver. The NCSA webserver wikipedia page says that NCSA httpd ran 95% of websites when apache took over, so I would say NCSA httpd is your answer.
Interestingly, this post indicates that the Apache foundation now advances a completely different derivation for the name.