- Sophos is one of the largest anti-virus vendors in the world, and the largest in Europe. Sophos's increasingly rapid growth internationally is reflected in a user base of well over five million and revenues which soared by more than 70% in the year 1999-2000. Sophos Anti-Virus, the company's flagship product is sold and supported in over 120 countries through a global network of subsidiaries and partners.www.sophos.com