Powerful plugin that takes your WordPress.org powered site beyond the blog with social-network features like user profiles, activity streams, user groups, and more.

GPL-2.0

PHP

Chitchatter

Peer-to-peer chat app that is serverless, decentralized, and ephemeral.

GPL-2.0

Nodejs

Convos

Always online web IRC client.

Artistic-2.0

Perl

DavMail

POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any mail/calendar client with an Exchange server, even from the internet or behind a firewall through Outlook Web Access.

GPL-2.0

Java

Discourse

Advanced forum / community solution based on Ruby and JS.

GPL-2.0

Docker