From Eclipsepedia

STP depends on a whole load of other projects! Here are the 3.4M7 dependencies that you will need to construct the 'platform' upon which you can build and use STP project technologies. All of the links below go through to the mirror mechanisms for large Eclipse downloads and they also point to the runtime versions of the projects, not the SDKs.

Eclipse Platform 3.4M7

WTP 3.0M7

EMF 2.4.0M7

EMF-XSD 2.4.0M7

EMF Query 1.2.0M7

EMF Transaction 1.2.0M7

EMF Validation 1.2.0M7

OCL 1.2.0M7

JET 0.9.0M7

GMF 2.1.0M7

GEF 3.4.0M7 (this is an SDK)

JDOM 1.0 (this is a direct link)