Skype
Freemium
Skype is an instant messaging and VOIP (Voice Over Internet Protocol) client to communicate with people in a distant place.
Slack
Freemium
Slack is a cloud-based team collaboration tool.
Trillian
Freemium
Trillian is a proprietary multiprotocol instant messaging application.
Discord
Free
Discord is a freeware proprietary VoIP application designed for gaming communities.
Empathy
Open Source
Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication ov…
Wire
Free
Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser cl…
Rocket.Chat
Open Source
Rocket.Chat free open source chat solution.
Matrix.org
Open Source
Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with…
QuteCom
Open Source
QuteCom (WengoPhone) is a free-software SIP-compliant VoIP client.
Wickr
Free
Wickr is an instant messenger application.
Tkabber
Open Source
Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI.
Telegram
Free
Telegram is a free cloud-based instant messaging platform.
Tox
Open Source
Tox is a peer-to-peer instant-messaging and video-calling protocol that offers end-to-end encryption.
Viber
Freemium
Viber Free Messenger and Phone Calls.
Signal
Open Source
Signal is the most scalable encryption tool.
Mattermost
Open Source
Mattermost is an open source, private cloud Slack-alternative, Workplace messaging for web, PCs and phones. MIT-licensed.
ICQ
Free
ICQ is an open source instant messaging software.
Instantbird
Open Source
Instantbird is a cross-platform instant messaging client based on Mozillas XULRunner and the open source library libpurple used in Pidgin.
Zoiper
Freemium
Zoiper is an easy to use sip video softphone, with excellent voice quality and easy to setup.
Dialog Messenger
Free Personal
Dialog Messenger is a handy and feature-rich enterprise multi-device messenger available for server or cloud.
Gitter
Freemium
Gitter is an open source instant messaging and chat room system for developers and users of GitHub repositories.
Toky
Freemium
Toky is an automation platform.
Compare Zulip with alternatives
Compare Dialog Messenger and Zulip and decide which is most suitable for you.