OnionCat creates a transparent IPv6 layer on top of TOR's hidden services. It allows users to anonymously access Internet services. It transmits any kind of IPv6-based data transparently through the TOR network on a location hidden basis. You can think of it as a point-to-multipoint VPN between hidden services. OnionCat is a stand-alone application which runs in userland and is a connector between TOR and the local OS. Any protocol which is based on IPv6 can be transmitted. Of course, UDP6 and TCP6 (and probably ICMP6) are the most important ones but all other protocols can also be forwarded through it. OnionCat's main purpose is to allow any user an easy use of hidden services and to allow hidden service providers to provide any type of service. Because OnionCat is IPv6-transparent the client applications may not be configured in any special way (SOCKSifying) because to every hidden service a unique IPv6 address is assigned by OnionCat. It creates an Internet within the Internet with the major advantage of being location hidden! This task is accomplished by resolving an IPv6 address to an .onion URL and then opening a connection to the desired hidden service. OnionCat creates the major advantage of using TOR's hidden services like usual IP hosts on the Internet. You can provide and use any service you could provide on the Internet, SMTP, DNS, HTTP, Torrent, whatever. It's end-to-end encrypted. Its architecture guarantees that the real IP of users cannot be revealed in any way. Together with OnionCat an "Internet within the Internet" could evolve.