It is possible (and recommended, in fact) that you develop your RCP application from a target that’s separate from your development environment. By default, when you build plug-ins using Eclipse, you develop against the set of plug-ins that are installed in your development environment. However, using the PDE preferences page, you can setup a completely separate directory containing an Eclipse target with only the plug-ins your application really needs.
The benefits of this are (at least) three fold:
First, you can build against a different version of RCP. That is, you can use one version of Eclipse to develop applications that run in a different version. As it sits today, you can use Eclipse 3.2 to develop Eclipse 3.0 and 3.1 applications. This means that you don’t necessarily have to upgrade your applications just because you’ve upgraded your development environment.
Second, by creating a totally separate target, you can very carefully control the set of plug-ins that your code has access to. If it’s not in the target, you can’t use it. This introduces a challenge however: you have to move the set of plug-ins (beyond what is provided in the RCP SDK) you need into the target. If you need to use, for example, the forms API, you’ll have to identify the plug-in that contains it (org.eclipse.ui.forms) and copy that plug-in to your target directory.
Third, when you install the RCP delta pack, you can install it on your target rather than cluttering up your development configuration (the RCP delta pack lets you package applications for platforms other than your development platform).
How you set up a target is described in the RCP FAQ. Thanks to Nick Edgar for providing a link to this information.