Skype
Freemium
Skype is an instant messaging and VOIP (Voice Over Internet Protocol) client to communicate with people in a distant place.
Tox
Open Source
Tox is a peer-to-peer instant-messaging and video-calling protocol that offers end-to-end encryption.
Signal
Open Source
Signal is the most scalable encryption tool.
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…
qutIM
Open Source
qutIM is free and open-source multiprotocol (ICQ, Jabber, Mail.Ru, IRC, VKontakte) instant messenger.
Zulip
Open Source
Zulip is a chat and collaborative software.
Telegram
Free
Telegram is a free cloud-based instant messaging platform.
Viber
Freemium
Viber Free Messenger and Phone Calls.
Jitsi
Open Source
Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.
Linphone
Open Source
Linphone is a free voice over IP (VoIP) service and SIP client.
ICQ
Free
ICQ is an open source instant messaging software.
Bit Chat
Open Source
Bit Chat is a secure, peer-to-peer, open source instant messenger with end-to-end encryption.
YakYak
Open Source
YakYak is a desktop chat client for Google Hangouts.
