This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
No, you just need to install a single web server (eg. Apache, Tomcat, Resin or whatever). For each user setup a configuration file for the server and place it in his/her home directory somewhere. Then write start/stop scripts which start an instance of the software using the config from the user's own directory.