http://jung.sourceforge.net/#!
http://www.netdisco.org/
http://sourceforge.net/projects/toponet/
http://www.ohloh.net/p/toponet
http://www.nero.net/projects/netviewer/
https://osl.uoregon.edu/redmine/projects/netdot
http://community.zenoss.org/index.jsp
http://www.cs.cornell.edu/cnrg/topology_aware/discovery/argus.html