The RCP downloads are meant as a base for building Eclipse RCP applications.  
As such, they do not include an application of their own and simply running the 
RCP install will do nothing.

This build requires a 64-bit JVM, and will not run with a 32-bit JVM.
You can, for example, use the Sun 64-bit 1.5 JVM for AMD64.  Note
that the Sun 1.4.2 JVM for AMD64 is 32-bit and therefore cannot be
used to run this build.