To install these plugins, point Eclipse at this site.
GEF SDK 3.5.1: contains runtime, source, and documentation.
GEF SDK 3.7.2: contains runtime, source, and documentation.
GEF SDK 3.6.2: contains runtime, source, and documentation.
GEF SDK 3.2.2: contains runtime, source, and documentation.
GEF SDK 3.3.2: contains runtime, source, and documentation.
GEF SDK 3.4.2: contains runtime, source, and documentation.