The best replacement for web server is application server.

The best alternatives to web server are rated as following:
★★★★★  application server
★★  web browser
★★  app server
★★  http server
★★  web container
★  server
★  database server
★  web client
★  web service
★  web host
★  file server
★  web hosting
★  container
★  web page
★  iis
★  web application server
★  ftp server
  cloud server
  tomcat
  application
  proxy server
  servlet container
  client
  windows web server
  web services
  streaming server
  apache

Your alternative for web server is not listed? Suggest!
Speaking about web server, one probably shouldn't forget about php.

Other search terms related to web server and their ratings are:
★★★★★ php
★ asp
freenas
ssl
You have in mind a companion for web server and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of web server in all years. Click on graph for more.
web server
application server
web browser