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Dialog Messenger is a corporate messenger for teamwork and secure communication.

Mattermost is an open-source, self-hostable enterprise team collaboration and messaging application. The software can be deployed to on-premis or to cloud instances. Mattermost is designed for internal use within organizations and businesses in financial services, government, healthcare, remote work, and enterprise DevOps, where teams use Mattermost to power collaboration at every stage of the DevOps lifecycle.

Jitsi is an open-source project and software toolset that allows you to easily build and deploy secure video conferencing solutions. At the heart of Jitsi are Jitsi Videobridge and Jitsi Meet, which let you have conferences on the internet, while other projects in the community enable other features such as audio, dial-in, recording, and simulcasting.  Jitsi supports popular protocols such as SIP, XMPP/Jabber, ICQ/AIM, Windows Live, Yahoo!, Google Hangouts, OTR, ZRTP and more.

Zoom is a commercial video and web conferencing software that can be used for webinars or team collaboration and communication. The software is developed by the Chinese and American company Zoom Video Communications, Inc. Zoom provides a cloud platform that is used and loved by many enterprises and fortune 500 companies, due to the easy-of-use and infrastructure-less nature of the platform.

WeChat connects a billion people with voice calls, video calls, photo sharing, chats and payments. The multi-purpose application is developed by the Chinese company Tencent and is and in China, it is described as "the app for everything". WeChat is primarily developed for the mobile consumer, but is also avalible on desktop and in the browser.

Viber is a cross-platform voice over IP application that allow people to make free and secure calls and messages to anyone, anywhere. With Viber, you can create group chats and make group calls, send stickers and emojis over chats that are 100% synced between devices, including 1-tap transfer of calls. Viber is available for free on Android, iOS, macOS, Linux and Windows.