avast! AntiVirus 5 Professional Edition is a collection of award winning, high-end technologies that work in perfect synergy, having one common goal: to protect your system and valuable data against computer viruses, spyware and rootkits. It represents a best-in-class solution for any Windows-based workstation. avast! antivirus is in use in around 50 million homes and offices worldwide; is specifically engineered to have low system requirements and to automatically and incrementally update both the program and virus definitions, so that they are always up-to-date.