Core features:

• 3d traceroute display: multiple graphics modification options
• statistics window: min, max, average, standard deviation and
  history window with destination ping time
• as list: the usual data view with lots of features
• long period Ping and HTTP monitor
• Whois query: everything with only one click
• record and playback: record any trace and playback step by step
• build in browser: and the browser is already built in.
• ASN inspector
• NSLookup: with UDP and TCP. And zone transfer capability.
• Day and Night trace: Admins beloved toy
• Command-line execution mode: full replacement for good old buddy tracert.
• passive OS fingerprinting
• three different Portscanner (knows 3,612 well known ports)
• analyze eMail headers: against RBLs
• Connection viewer: TCP, IP, UDP etc. statistics
• HTTP Spy: query HTTP-headers and webpages
• Atomic Clock Sync
• ISO 3166 code browser
• build in TELNET client
• low CPU-Usage
• everywhere a usefull context menu
• Working with Windows 2000 and Windows XP, XP SP1 und XP SP2
  (perhaps with Windows 98, 98SE or ME and NT4)

And best of all: It's free. No money, no postcards, no beer. Just free. It is spyware free, no adware, nothing. Just free.

And for the PROs there is the Pro-Version with its . You will get much more exciting features.