AVG Technologies

Formerly Grisoft, AVG Technologies' key program is its AVG anti-virus line of programs. AVG has been around since the early 1990's.

When it started, AVG was one of very few free anti-virus programs. The market was dominated by paid programs by Norton, Symantec and McAffee.

Now there are many free Windows anti-virus programs to choose from, including one from Microsoft themselves.