This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
EAR files are not "server specific", but they may contain configuration files specific to a server. JBoss configuration files, Weblogic configuration files... So an application developped for Weblogic may not work under JBoss without tuning.