Please note that GSIM v2.0 is now available, and that more information about clickable diagrams can be found here. GSIM v2.0 supersedes v1.2.
Clickable GSIM is an interactive way to explore GSIM. There are a number of views through which you can explore. You can look at the entire model on the "GSIM on a page" view, or you can explore the objects in each GSIM group (Base, Business, Concepts, Exchange and Structures).
On these broad views of GSIM, you can click on any objects and it will take you to a page which shows you what other information objects it is related to, as well as the definition and attributes of the object. You can also go straight to the page for an individual object from the list of objects shown in the left hand navigator.