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Asana is a web and mobile collaborative work management app that goes beyond typical collaboration software by enabling teams to track everything they're working on. With tasks, projects, conversations, and dashboards, Asana lets your team know who's doing what by when to help you get results. Use Asana for team communication, setting meeting agendas, running brainstorms, sharing files, or creating shared calendars--anything you can think of. You can also add partner integrations to customize Asana for your team with functionality like Gantt charts, time-tracking, and Google calendar sync. Asana is available on web, iOS, and Android and is free for teams of up to 15 people. »

Mattermost is an open source, self-hosted Slack alternative.

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.

HipChat is an instant messaging service designed for companies and teams. It has persistent chat rooms, one-to-one chat, searchable chat history, file sharing via drag & drop and clipboard, inline image previews, an API, chat over SMS, and more.

Self-hosted chat for small teams.

Gitter is a chat and collaboration tool for developers and users. It's a place for developers to talk.

eXo Platform is a cloud-ready enterprise portal and user experience platform-as-a-service (UXPaaS) for building and deploying transactional websites, managing web and social content and creating gadgets and dashboards. Built on open standards and open source technologies, eXo Platform has the features and extensibility of a UXP and the cloud architecture to build public and private clouds.

Zulip is a group chat app.

With Samepage, you can put all your project information on one page and collaborate with your team in real time. Samepage brings together an entire suite of project management tools, awesome communication features, and built-in integration with the apps you use. Everything you need to move projects forward, without leaving Samepage.

Spaces is an app for small group sharing.

Gettick is a simple environment that provides managers with a complete overview of the project, while giving the team everything they need to work on the project. Thanks to the Gettick you will not need anything else so you will save a lot of time an money for other limited tools.

Open Source private chat server. Your own private Chat server in minutes, plus additional features. No credit card required.A fast, secure and stable solution based on Rails.