This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
If your application is to have JSPs (that are not pre-compiled) you will need a full JDK. JSPs get converted to servlet code and then compiled by the container when they are first accessed. For this reason, you will need a compiler.
Version 5.5 ships with the JDT compiler (from the Eclipse project) and therefore, only needs a JRE.