This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Servlet was designed to be used as an Interface to be implemented on any protocol.
Technically Servlet supports most of the commonly used protocols
Stated like that, this is really not correct. The request/response architecture of the servlet API limits it to those protocols that can reasonable be used that way, and many common protocols just can't. In practice, no servlet implementation exists that supports anything but HTTP/HTTPS and -more recently- SIP.