Does anyone out there have a recommendation for a good network topology mapping application ?

I want to see a live layer 2 and 3 ��topology diagrams - routing and vlans etc.

juniper space used to have such a plugin but they killed it :(

the only other mention of an app capable of such a thing that I have heard of is solar winds .

Any advice or experience with such an app would be much appreciated.

cheers

Hamish