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Pro Public servers
BitlBee can be used without installing via community-maintained public servers.
Pro Supports multiple protocols and networks
BitlBee supports: XMPP/Jabber, MSN Messenger, Yahoo! Messenger, AIM, ICQ, and Twitter.
Pro Free and open source
BitlBee is available for free and licensed under GPLv2 with source code available on GitHub.
While the help command is informative and includes examples, settting BitlBee up requires a considerable amount of technical knowledge.