Adium Alternatives for Windows

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

Tox is a peer-to-peer instant-messaging and video-calling protocol that offers end-to-end encryption.

Trillian is a proprietary multiprotocol instant messaging application.

Digsby provides you with IM, email and Social networks in one easy to use application.

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

Imo free video calls and chat is a kind of Communication apps for Android.

Facebook Messenger is the official Facebook app that lets you have text conversations with all of your friends on the popular social network.

HexChat is an open-source, cross-platform IRC client.

Psi is a free instant messaging application designed for the XMPP network (including Google Talk). Fast and lightweight, Psi is fully open-source and compatible with Windows, Linux, and Mac OS X.

ICQ is an open source instant messaging software.

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.

Quassel IRC, or Quassel, is a graphical, distributed, cross-platform IRC client.

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

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.

KakaoTalk (Korean: 카카오톡), or sometimes KaTalk, is a free mobile instant messaging application for smartphones with free text and free call features.

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.

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.

Bit Chat is a secure, peer-to-peer, open source instant messenger with end-to-end encryption.

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

YakYak is a desktop chat client for Google Hangouts.