Any Java programming environment is suitable to develop mcmTheater programs. NetBeans and eclipse are both freely available full fledged integrated programming environments. They provide the professional with a host of usefull features but can be confusing for the beginning programmer.
DrJava on the other hand was developed expressly for teaching purposes at Rice University in Houston, TX. It is a small, yet powerful Java programming environment, and does not distract the beginning user with many panes, windows, views, ... One of its most usefull features is the Interactions pane. A user can type Java commands in this pane which are instantly executed. This is an excellent mode of developing an understanding of the Java language itself as well as testing Java code.
The mcmTheater startup kit contains a copy DrJava along with two DrJava project file examples. DrJava's web site contains User Documentation that explains how to edit, compile, and run programs, see Quick Start Guide.