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