The ICQ logo that was originally created was used from 1999 until 2014 with the ICQ99a/b being the very first time that many people around the globe could use an instant messaging system.
The ICQ 2000 added reminder as well as features of note.
Then in 2001, other features were added including a server side storage for the users contact list. This provided users with the ability to sync their contact on more than one computer.
AOL Time Warner stated the United States patent office issued their company a patent for instant messaging programs on December 19, 2002. Also during this year, this was on the last ICQ version that was free from any type of advertisements.
Next came what was known as ICQ Pro 2003b and was the very first version that used the protocol version 10. Other versions like ICQ 5 and ICQ 5.1 did not use version 10 but instead used a version of the protocol. ICQ 2002, as well as 2003a, used the 8 version protocol. The early versions of ICQ all used version 7 of ICQ protocol.
ICQ 4 and ICQ 5 were nothing more than upgrades of the ICQ Lite. However, there were a few additions such as Xtraz giving the younger one’s games to play. The idea behind the lite program was that it was a faster download and was better for computers that were slow.
ICQ 5 was the first to offer skins support. On the other hand, ICQ 6, saw more updates than what was seen with ICQ 5 offering the engine that was used in AIM Triton and was designed using Boxely. The new features included the chance to send instant messages right to those on their client list without much effort.
Now that ICQ 6 is available, other versions will not work unless users make the upgrade and of course enjoy all the new features.