Sandboxed Tor Browser aims to isolate Tor Browser from other processes of the operating system in order to limit its ability to interact or query low-level APIs. In this way the experts believe it is possible to reduce the surface of attack of the Tor users, making hard for attackers the exploitation of flaws that could lead to the exposure of real IP addresses, MAC addresses, computer name, and other data that can be used to de-anonymize users. This version is still an alpha version that could include some potentially major bugs.”]
Source: http://securityaffairs.co/wordpress/54319/digital-id/sandboxed-tor-browser.html