FFT is an alternative traceroute program for displaying the route packets take to an IP network host. Unlike Van Jacobson's traceroute, which is available on almost every platform today, FFT uses TCP in order to elicit ICMP TIME_EXCEEDEDs or TCP_RST. As a result, FFT often executes much faster and sees behind some configurations of packet- filter based firewalls. FFT has been around since 1998, but this is its first release on Darwin/MacOSX. The source code is available.