Slack - A messaging app for teams who see through the Earth!
Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.
Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited
Ripcord - A desktop chat client for Discord and Slack
Glip - Glip is fully searchable, real-time group chat & video chat, task management, file sharing and more, in one easy-to-use app. Get started FREE today.
Bitrix24 - Bitrix24 is a free (for small businesses) social enterprise platform. It is a united work space which handles the many aspects of daily operations and tasks. Create your own social intranet in minutes!