IDE was discontinued a few months ago when the transition to the new architecture was complete.
The official web interface to your smartthings account is now at
Here is the official announcement of the change
NEW Advanced User App for SmartThings Web!
However: the new web interface does not yet provide network mapping of any kind, not even the minimum amount we had with the old IDE. 
A number of people have asked, but there has not yet been any official response as to whether a map topology feature will eventually be added or not.