This chapter is going to use the most recent beta of Eclipse 3.0, milestone build 6. Eclipse 3.0 is being designed to be as compatible as possible with Versions 2.0 and 2.1, and the update team says, "We will provide a comprehensive Eclipse 3.0 Porting Guide that covers all areas of breaking API changes, and describes how to port existing 2.1 plug-ins to 3.0." You'll also be able to import 2.0 and 2.1 projects into 3.0, but you'll get a dialog saying that the project needs to be modified and probably won't work with earlier versions after that, so make sure you copy your projects first.