Free Network Utilities & Research Tools	Source code
Whois Lookup. Get Whois records automatically for domains worldwide.  Supports almost all TLDs.
Domain Check. See if a domain is available by checking both WhoIS and DNS databases.
Ping. See if a host is reachable by sending a ICMP packet to them and timing it.
NsLookup - DNS Query. Look up various domain (DNS) resource records with this version of the classic NsLookup utility.
TCP/IP Port Query. Grab a web page, look up a domain, and more.  Test certain ports on your machine to see if there is a response.
Traceroute. Trace the path from this web server to another server on the Internet somewhere.
Traceroute with Analyze Path graph. Do a simple, graphical traceroute showing time for each hop.
Email Dossier. Validate and investigate email addresses.  This utility will contact the remote mail server for a more thorough check.
Browser Mirror. See what your browser reveals to other parties whose websites you visit.