Gitter!

Riot (formerly Vector) is an opensource interoperable app running on Web, iOS and Android. It is built around chat rooms, both public and private and provides messaging, filesharing, voice and video conferencing (beta on Android and web), integrations to tools like GitHub, Jira, Jenkins and much more soon. Vector is built on the Matrix.org open standard which provides bridges to other systems such as Slack, IRC and a lot more soon. One can use the hosted service or run their own. »

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

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.

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.

dialog app is built and designed for corporate communication on all types of mobile devices - tablet, mobile phones etc.

Campfire is a simple web-based real-time group chat tool for business. It makes real-time communication with 2-60 people as simple as visiting a web page.

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.

TribeScale is a startup that aims to enhance teamwork in companies through the improvement of communication, coordination, and the pace on the basis of targets set. It is designed by taking as a reference the methodologies of the most innovative teams in the world: (Apple, Tesla, Google, Virgin...).Companies that use TribeScale have said that it has ended with 80 percent of working meetings. We are a platform for communication and management of teams very advanced and action-oriented, with functionalities such as creating and assigning tasks, sending surveys, decision-making, and automation of processes. »

MongooseIM is aimed at large, complex enterprise level projects, where real-time communication is critical for business success. It provides high availability, ease of deployment, development and reliability in production.

Wiggio is an online toolkit that makes it easy to work in groups. With Wiggio you can: - keep shared calendar (with text message reminders) - poll group in real-time - send mass text messages - store files in one common folder - setup group conference call - many others!

AVAILO is a business communication app for teams. One place for internal and external communications, open groups for your team members, service providers and customers, with real time messaging, share emails, folders and files, in a simple way.