Utopia

vs

Dialog Messenger

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.

Skype is a telecommunications application that specialize in providing video chat and voice calls between computers, tablets, mobile devices and consoles. The software allows you to connect with friends and business colleges worldwide. Skype provides free online calls, messaging, affordable international calling to mobiles or landlines and Skype for Business for effective collaboration among teams.

A VoIP application and platform designed for creating communities and connecting gamers, and people rallying around specific causes. The Discord client is a free to use and can handle text, image, video and audio communication between users in a chat channel. Currently over 250 million users use the software to connect with others across the globe.

Element is an All-in-one secure chat app for teams, friends and organisations that allow you to own your conversations. With Element you can keep conversations in your control, safe from data-mining and ads. Element utilize the open and global Matrix network for message relay, protected by proven end-to-end encryption.

Signal is a cross-platform encrypted messaging application that has a strong focus on privacy. The application is developed by Signal Messenger LLC and provides users with features like one-to-one and group messages, which can include files, voice notes, images and videos. The software is famous for being used by the whistleblower and privacy advocate Edward Snowden who once said "I use Signal every day, it is the most scalable encryption tool we have".