If you're not installing into an existing Eclipse, you'll need one.
Eclipse Indigo 3.7.x or Indigo based suite such as SpringSource Tool Suite 2.9.x
Eclipse Juno 3.8/4.2
Eclipse JEE Indigo recommended.
Select Help>Install New Software..
Enter one of the Virgo update sites below.
Select "Virgo Tools" feature and click install.
Many users will also want to install the M2E release at: <code> http://download.eclipse.org/technology/m2e/releases</code>. (You'll need this to run the greenpages examples.)