PacketX

PacketX is a small COM class library that makes it easy to use WinPcap packet capture functionality from almost any modern programming language supporting ActiveX technology.
PacketX uses WinPcap Packet Driver API implemented by packet.dll and BPF filtering support from pcap.dll.

This means that you can use PacketX to capture, send (and optionally filter) packets and collect network statistics. PacketX cannot be used to block network traffic to build a firewall.

The library contains an ActiveX control that can be used from RAD development tools like Microsoft Visual Basic or Borland Delphi. For scripting languages there are corresponding lightweight COM classes