Adium Icon


Type: Proprietary
Identity: Universal Internet Number / Unified Identification Number / Unique Identification Number (UIN), e.g. 12345678
Interoperability: AIM, MobileMe (formerly known as .Mac)
Popularity: Germany, Eastern Europe
Default server; port: (formerly, which no longer works for ICQ); 5190


When it was released in 1996 by a company called Mirabilis, ICQ was the first real popular Instant Messaging service. In 1998, AOL bought Mirabilis and later made the ICQ protocol more similar to the AIM protocol.

In 2010, AOL sold ICQ to the proprietors of The new owners changed the login server address to; 1.4.1 is the first version of Adium to use the new address by default, but older versions can be reconfigured by double-clicking on each ICQ account in the Preferences window and changing each account's Login Server in the Options tab.


ICQ servers filter strings containing <script, a tag in the Hypertext Markup Language (HTML), which AIM and ICQ use to encode messages (so as to support fonts, colors, etc.).

HTML tags that you put into the inputline are “escaped” by Adium, so that the recipient's client will not attempt to use the HTML tag; it will simply display the text of the tag. However, it appears that the AIM/ICQ server drops messages containing even escaped HTML (but only that tag — other tags work fine).