Another popular program in the Windows antivirus world, avast!, does have an Apple version. This is a virus checking software program for Mac that can be quickly downloaded online and easily installed by following the basic prompts. Most Apple operating systems are supported by avast! except Mac OS X 10.0, 10.1, 10.2 and 10.3, which aren't supported. The antivirus program also does not support any operating systems before Mac OS X.
Users must pay for each avast! license used and renew annually. One, two and three year subscriptions are offered. Those running Windows and Mac on the same computer can purchase an avast! program that protects both operating systems.
As of February 2010, a one-year license for Mac only cost $39.95. Two-year Mac-only licensing costs $57.94; three-year licenses cost $74.13. You might also want to order a backup CD or DVD for an additional $9.95 in case something happens to your computer and you need to reinstall the program; the licensing prices only cover a one-time download.
avast! Mac Edition
http://www.avast.com/mac-edition