To install these plugins, point Eclipse at this site.
GMF SDK 2.1.0RC5 S200806121402: contains runtime, source, and documentation.
GMF SDK 2.2.2RC4 S201002172021: contains runtime, source, and documentation.
GMF SDK 2.3.0M6 S201003171034: contains runtime, source, and documentation.
GMF SDK 2.1.0RC5 S200806121402: contains runtime, source, and documentation.
GMF SDK 2.2.2RC4 S201002172021: contains runtime, source, and documentation.
GMF SDK 2.3.0M7 S201005041559: contains runtime, source, and documentation.