cheops / cheops-ng : Gives a simple interface to many network utilities, maps local or remote networks and identifies OS of machines
Cheops provides the functionality of many network utilities through a comfortable, powerful GUI. It has host/network discovery functionality as well as OS detection of hosts. Cheops-ng has the ability to probe hosts to see what services they are running. On some services, cheops-ng is actually able to see what program is running for a service and the version number of that program. The original Cheops program is currently not being developed or maintained so users are advised to use cheops-ng.
Fping : A parallel ping scanning program fping is a ping(1) like program which uses the Internet Control Message Protocol (ICMP) echo request to determine