Slack puts all your team communications in one place wherever you go with real-time messaging, file sharing, and one-to-one and group conversations.
Real-time messaging, file sharing, supporting one-to-one and group conversations
Powerful search and archiving, meaning no one is ever left out of the loop
Dozens of integrations with tools including Dropbox, Asana, Google+ Hangouts, Twitter, Zendesk
New integrations and features added frequently
Inline images and video, with rich link summaries giving context without leaving the app
Instantly synced across all devices
Configurable notifications for desktop, mobile push, and email
Scientifically proven (or at least rumored) to make your working life simpler, more pleasant, and productive.
Slack is free for an unlimited number of users, and an unlimited amount of time, with upgradable plans for extended message history, unlimited integration, file storage, and customizable data retention policies.