There are not many viruses in the world that actually infect a Macintosh system. Some feel its the result of it being a superior operating system. Others feel it has more to do with Macintosh owning such a small percentage of the marketshare that there aren't enough of them in the world to make a worthwhile target. Even if the Mac doesn't tend to get infected by most viruses, it can still host infected files or pass infected files along. Many corporations have policies dictating that all computers on the network have antivirus software installed and running at all times. Sophos will soon release their version of antivirus software for the Mac OS X platform. Read More.