OSCAR protocol - Definition and Overview

OSCAR is AOL's instant messaging protocol standing for Open System for CommunicAtion in Realtime. Despite its name, the specifications for the protocol are proprietary. AOL has gone to great lengths to keep competitors, namely Microsoft and Cerulean Studios, from implementing compatible clients for their proprietary messaging system.

Currently OSCAR is in use for AOL's two main instant messenging systems: ICQ and AIM. OSCAR is currently a binary protocol. Large parts of the protocol are nowadays understood after reverse-engineering the protocol, implemented by an ever-increasing number of clients. Apple's iChat is the only officially licensed non-AOL client.

See Also

• Comparison of instant messengers
• TOC protocol, AOL's free yet deprecated messaging protocol

External links

Protocol information

• OSCAR Protocol Terminology (http://www.aim.aol.com/javadev/terminology.html)
• OSCAR/ICQ Protocol Specification (http://www.stud.uni-karlsruhe.de/~uck4/ICQ/) (user editable)
• OSCAR (ICQ v7/v8/v9) Documentation (http://iserverd1.khstu.ru/oscar/)
• OSCAR Documentation Wiki (http://joust.kano.net/wiki/oscar/)

Implementations

• A Free Java Implementation of OSCAR (http://joust.kano.net/joscar/)
• A Free Perl Implementation of OSCAR (http://search.cpan.org/search?dist=Net-OSCAR)
• A Free OCaml Implementation of OSCAR (http://www.cgorski.org/mloscar/)
• A free Delphi Implementation of OSCAR (http://www.ithilien.tk/)
• Adium (http://www.adiumx.com/)