ICQ is one of the most popular instant messaging programs. This program is official, which means that it is fully compatible with the ICQ protocol. The program is simple to use, has lots of features and consumes low traffic. The last point is particularly important for owners of expensive and slow Internet. It supports most of emoticons and animations. There is an invisible status as well to ensure you are not distracted from work. Contacts can be sorted by groups, making access much easier. This is especially true for people who have large contact lists.