The PPTP (Point-to-point tunneling protocol) was made by a company called Microsoft to connect to a foreign network (Virtual Private Network). Nowadays it is used by some ADSL ISPs around the world and some brave companies that refuse to use something more secure like IPSec.
This application is actually a user interface frontend for C. Scott Ananian's pptp-linux, which was ported to FreeBSD (and thus to Darwin) by John Polstra.