Top Alternatives to Psi

Pidgin is a free and open-source chat client which supports AIM, Google Talk, ICQ, XMPP protocols.

Telegram is a free cloud-based instant messaging platform.

Adium is an Open source multi-protocol instant messaging client for Mac OS X, supports MSN, Jabber, Yahoo! and other networks.

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Miranda IM is an open source multiprotocol instant messaging application, designed for Microsoft Windows.

Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication over various IM protocols.

IM+ supports simultaneously major IM services, including Google Talk, Twitter DMs, Yahoo!, AIM/iChat, ICQ, Jabber (and Slack through Jabber), etc.

Kopete is a multi-protocol, free software instant messaging client released as part of the KDE Software Compilation. Although it can run in numerous environments, it was designed for and integrates with the KDE Plasma Workspaces.

Gajim is an instant messaging client for the XMPP protocol which uses the GTK+ toolkit.

Miranda NG is a successor of Miranda IM, a popular multi-protocol instant messaging client for Windows.

Instantbird is a cross-platform instant messaging client based on Mozillas XULRunner and the open source library libpurple used in Pidgin.

iMessage is an instant messaging service.

Xabber (XMPP and Jabber) is a XMPP client for the Android Operating System.

Bitmessage is a decentralized, encrypted, peer-to-peer, trustless communications protocol that can be used by one person to send encrypted messages to another person, or to multiple subscribers.

Apache Spark is an open-source cluster-computing framework.

qutIM is free and open-source multiprotocol (ICQ, Jabber, Mail.Ru, IRC, VKontakte) instant messenger.

Psi is a cross-platform powerful XMPP/Jabber client (Qt, C++) designed for the Jabber power users. Psi+ is a development branch of Psi IM XMPP/Jabber client.

Conversations is an open source XMPP/Jabber client for the Android platform.

Tencent QQ (QQ) is an instant messaging software service.

Kadu is a free and open source multi-platform instant messaging client that supports Gadu-Gadu, XMPP IM networks and other services based on XMPP like Google Talk.

Coccinella is a free and open-source cross-platform client for the XMPP/Jabber-instant messaging-protocol.

Disa is your new messaging hub. Conversations from different services can seamlessly be joined together, or disbanded within seconds.

Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI.