This place is the Geclipse Testing project update.
To install the plugin manually:
1º - Download the rar file from here.
2º - Unrar the file inside the Eclipse folder.
To install eclipse directly with the update manager of Eclipse use the next http address:

http://geclipse.users.sourceforge.net/

To do that:
1º - Select "Software Updates" in the menu "Help"


2º - In the flap "Avaliale Software" select "Add Site..." and use the address: "http://geclipse.users.sourceforge.net/" and click the OK button


3º - In the tree appear the site "http://geclipse.users.sourceforge.net/" with the elements "GeclipseFeature Feature 1.0.0" and "EclEmma Java Code Coverage 1.3.0". Select both. Finally select the button "Install..." and follow the instructions of Eclipse.
(NOTE: Geclipse is incompatible with the new versions of EclEmma, if you have a newer version, please remove it first and install the version 1.3.0)