VTun - Definition from the Hotspot Shield Glossary
VTun stands for Virtual Tunnel and is an application for networking and is used to establish Virtual Tunnels over a standard TCP/IP network. The application has support for IP (Internet Protocol), PPP (Point to Point Protocol) and SLIP (Serial Line Internet Protocol) and is used on Unix operating systems.
The application is extremely easy to implement and setup and includes data compression (Deflate & LZO), encryption (BlowFish 128bit keys & challenge based authentication) and traffic shaping. The various versions of VTun are available for free download together with a configuration file for the application. VTun connections are created through a TCP connection between the client and server.