Open Source Instant Messengers

An encrypted messaging app focused on privacy, supporting texts, calls, photos, videos, files, and group chats, with no ads or trackers.

A secure collaboration app with end-to-end encryption and interoperability across web, desktop, and mobile. Includes chat, voice, and video calls.

Matrix defines a set of open APIs for decentralised communication, suitable for securely publishing, persisting and subscribing to data over a global open federation of servers with no single point of control.

Pidgin is a chat program which lets you log into accounts on multiple chat networks simultaneously. This means that you can be chatting with friends on XMPP and sitting in an IRC channel at the same time.

With the rise of widespread government monitoring programs, Tox is an easy to use application that allows you to connect with friends and loved ones without anyone else listening in.

SimpleX - the most private and secure chat and applications platform - now with double ratchet E2E encryption! Built on Haskell with Love and Coffee.

Jami (formerly GNU Ring, SFLphone) positions itself as a potential free Skype replacement

Stoat (previously Revolt) is a chat platform that puts users first. With text & voice channels, video calling, screen sharing, permissions, mod tools, bots & more. Join any community or build one just the way you like it. It also respects your privacy.

A secure, decentralized, peer-to-peer messaging app that works over Bluetooth mesh networks. No internet required, no servers, no phone numbers — just pure encrypted communication.

Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption.

Fossify Messenger is your trusted messaging companion, designed to enhance your messaging experience in various ways.

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.

Mattermost is a secure, open source platform for communication, collaboration, and workflow orchestration across tools and teams.

Station is the first open-source smart browser for busy people. A single place for all of your web applications.

All your services in one place, built by the community.

RetroShare is a open source cross-platform, private and secure decentralized communication system. It lets you to securely chat, share photos, videos, and more, using OpenPGP to authenticate peers and .

It is the brand new, and fastest ever, Matrix client. It is for personal and community use, and will support enterprise functionality later this year.

Molly is an independent Signal fork for Android.

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.

QUIK is an open source replacement to the stock messaging app on Android. It is a continuation of QKSMS.

FluffyChat is an open, nonprofit and cute matrix messenger app for Ubuntu Touch, Android and iOS.

Delta Chat looks and feels like other popular messenger apps, but does not involve centralized control, tracking or selling you, friends, colleagues or family out to large organizations. "Privacy by Design" has never been more fun.

Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].

Linphone is one of the most famous open source softphones in the world. It is fully SIP-based, for all calling, presence and IM features.

QKSMS brings a refreshingly beautiful and responsive Material Design touch to the stale state of text messaging.