GitHub - Linen-dev/linen.dev: Google-searchable Slack alternative for Communities - Linen is a Google-searchable community chat tool. Linen was built as an alternative to closed tools like Slack and Discord.
Trillian - The Swiss Army Knife of Instant Messaging. Trillian is a fully featured, stand-alone, skinnable chat client that supports AIM, ICQ, MSN, Yahoo Messenger, and IRC.
chat application with a client written in Flash. It makes use of to maintain a socket connection to an XML server.
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