Jigloo is a GUI builder. It is implemented as an Eclipse plugin available from www.cloudgarden.com.
To install Jigloo as an Eclipse plugin, use the Update Manager in Eclipse to download and install Jigloo - just open it (under "Help->Software Updates->Find and Install"). You will need to create a new remote site entry in the update manager for the Jigloo update-site - the url is: http://cloudgarden1.com/update-site.
For detailed help, visit http://www.cloudgarden.com/jigloo/index.html.