Jitsi Desktop (previously SIP Communicator) is a legacy audio/video and chat communicator with full encryption, precedessor of Jitsi Meet .
Jitsi Desktop is not actively developed anymore: last version, released in October 2017, can be still downloaded from GitHub. Its successor is Jitsi Meet
Go ahead, video chat with the whole team. In fact, invite everyone you know. Jitsi Meet is a fully encrypted, 100% open source video conferencing solution that you can use all day, every day, for free — with no account needed.
Skype is the most popular free voice-over IP and instant messaging service globally. It allows users to text, video and voice call over the internet. Users can also call landlines and mobiles at competitive rates using Skype credit, premium accounts and subscriptions.
WhatsApp is an iPhone and Android messaging app which allows you to exchange messages without having to pay for SMS.
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.
Zulip is a group chat app in which messages are threaded by topic, helping you have long-running, organized conversations. Zulip's threading makes it easy for people not always on chat (like managers, remote team members, contractors, part-time workers, etc) to weigh in on...
With Viber, everyone in the world can connect. Freely. More than 460 million Viber users text, make HD-quality phone and video calls, and send photo and video messages worldwide over WiFi or 3G - for free.
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 text messages on your phone.
Video conversations with up to 8 people in your browser - no downloads, no login. Just name your channel and you are on. Works in all modern browsers, even mobile.
Empathy is a messaging program which supports text, voice, video chat, and file transfers over many different protocols. You can tell it about your accounts on all those services and do all your chatting within one application.Discontinued
Empathy is currently unmaintained. Last version, 3.25, released in August 2017, can be still downloaded from the official website.