The Eclipse SDK 4.2, for the most part, contains all the plug-ins that make up Eclipse 3.7. That is, all of Java development tools (JDT) and Plug-in Development Environment (PDE), and most of the Platform, are the same bits as in 3.7. What's different is the implementation of the Workbench (org.eclipse.ui.workbench plugin), and the technologies this new implementation is based on. Before the release, the technologies (modeled user interface, dependency injection and service-based programming model, CSS-based styling) were called 'e4' but we are now referring to them as the Eclipse 4 Application Platform. On top of the Eclipse 4 Application Platform, the 4.x Workbench offers an implementation of the 3.x Workbench APIs, to provide backwards compatibility for the Eclipse IDE and its plug-ins.