Whonix(called TorBOX or aos in past) is an anonymous general purpose operating system based on Virtual Box, Debian GNU/Linux and Tor. By Whonix design, IP and DNS leaks are impossible. Not even malware with root rights can find out the user's real IP/location.
This is because Whonix consists of two (virtual) machines. One machine solely runs Tor and acts as a gateway, which we call Whonix-Gateway. The other machine, which we call Whonix-Workstation, is on a completely isolated network. Only connections through Tor are possible.
Whonix is produced independently from the Tor (r) anonymity software and carries no guarantee from The Tor Project about quality, suitability or anything else. Due to trademark issues the project was renamed to Whonix.
The project homepage with a full project description, threat model and documentation, build instructions can be found here:http://whonix.sf.net