ICQ is the first instant messaging and presence in the world, coming from Mirabilis. Bought by AOL. Now owned by Mail.ru. Now used mainly in eastern Europe. Privacy note: Russian government may have rights to access the logs under the law.
Connecting to ICQ with clientlogin requires a "devID" or "devKey". They can be obtained here. Official clients use the following keys:
|ICQ for Windows||7.2 (or earlier) to 7.5||gu19PNBblQjCdbMU|
|ICQ for Java||3.0.0||ic10GdI_eL50oMQ_|
|ICQ for Mac/Linux (Adobe AIR)||??||ic1-IIcaJnnNV5xA|
|ICQ for Windows Mobile||??||mi12f8a_qCj1okmC|
|ICQ for Android||1.0.1||ao1mAegmj4_7xQOy|