Sophos has just introduced a free antivirus for Mac users that can be installed to detect and block malware designed to attack Apple computers running Mac OS X.
Sophos AntiVirus Home Edition for Mac also detects malware written for Windows that Mac users can spread via email and USB drives, but not be infected.
The AntiVirus Home Edition for Mac solution is a non-commercial version of Sophos Anti-Virus 7.2 for Mac, targeted at home users and modified to be easy to use.
You can download if you want Sophos AntiVirus Home Edition for Mac from HERE.
Source: Verysecurity.net
Very good data, however, how good is this antivirus compared to others like ESSET and how heavy is it?