Slenke!

Wrike's end-to-end solution takes your projects from initial request to tracking work progress and reporting results. With Wrike, you'll be able to create and delegate tasks, track deadlines, visualize your plans on the Gantt chart, and share reports. If needed, you can use advanced features like Custom Workflows, advanced security, restricted data access and more. Wrike is a powerful yet user-friendly solution that helps you achieve your project goals.

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.

Wrike's end-to-end solution takes your projects from initial request to tracking work progress and reporting results. With Wrike, you'll be able to create and delegate tasks, track deadlines, visualize your plans on the Gantt chart, and share reports. If needed, you can use advanced features like Custom Workflows, advanced security, restricted data access and more. Wrike is a powerful yet user-friendly solution that helps you achieve your project goals.

Matrix.org is a growing ecosystem for open, decentralised chat, VoIP and IoT communication.

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.

Opensource task & productivity management tool for startups, engineered based on the concepts of OKR.

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.

hack.chat is a minimal, distraction-free chat application.Channels are created and joined by going to https://hack.chat/?your-channel . There are no channel lists, so a secret channel name can be used for private discussions.