Pidgin is an easy to use, multi-protocol chat client client used by millions. Connect to AIM, MSN, Yahoo, XMPP, and more chat networks all at once.

Slack brings all your communication together in one place. It's real-time messaging, archiving and search for modern teams.

Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.

Adium is a free and open source instant messaging application for Mac OS X, written using Mac OS Xs Cocoa API, released under the GNU GPL and developed by the Adium team.

Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as...

Digsby is a multiprotocol IM client that lets you chat with all your friends on AIM, MSN, Yahoo, ICQ, Google Talk, and Jabber with one simple to manage buddy list.

Message and video chat with your friends and family for free.

HexChat is an IRC client based on XChat for Linux , but unlike XChat it’s completely free for both Windows and Unix-like systems.

Meebo is integrated, all-in-one instant messaging (IM client) that connects you with your friends everywhere.

Unison is for business: a fast messenger and group collaboration tool that lets teams work much more quickly together, especially across different locations and time zones. It syncs instantly across your smartphone, tablet, or computer.

Matrix is an open standard for decentralized persistent communication over IP. It can be used for decentralised group chat, WebRTC signaling, IoT-data transfer, and generally to link together fragmented silos of communication.

Chat everywhere! IM+ is the most widely used mobile IM app! Connect all-in-one to MSN, Yahoo!, Google Talk, AIM, Jabber, ICQ, Facebook, MySpace and Twitter on ALL popular mobile platforms.

Free, open source and cross platform messaging and emailing app that combines common web applications into one.

tawk.to is a live chat app that lets you monitor and chat with visitors on your website or from a customizable page.

ICQ is one of the oldest instant messengers. First developed by the Israeli company Mirabilis, sold to AOL, sold again and currenly owned by the Russian "mail.ru" group (known for one of the largest social networks).

ChatSecure is a free and open source messaging app that features OTR encryption over XMPP.

Threema is a new mobile messaging app that puts security first. With true end-to-end encryption, you can rest assured that only you and the intended recipient can read your messages.

The goal of Gajim is to provide a full featured and easy to use Jabber client. Gajim works nicely with GNOME, but does not require it to run. It is released under the GNU General Public License.

Chat "off-the-grid" with people around you – even if there is no Internet connection or mobile phone coverage.

Snapchat is the fastest way to share a moment with friends. You control how long your friends can view your message – simply set the timer up to ten seconds and send.

Open source Jabber (XMPP) client with multi-account support, clean and simple interface. Being both free (as in freedom!) and ad-free, Xabber is designed to be the best Jabber client for Android .

Jitsi Meet lets you stay in touch with all your teams, be they family, friends, or colleagues. Instant video conferences, efficiently adapting to your scale.

Traditionally, chat clients on the Mac have been anything but glamorous. Colloquy is an advanced IRC, SILC & ICB client which aims to fill this void.

WeeChat is a fast, light and extensible chat client. It runs on many platforms (including Linux, BSD and Mac OS).

Wickr is a free end-to-end encrypted text, video, picture and voice messenger with full sender control.