Dazzle Quality Handbook.

One of our most used tools is Mattermost. Mattermost is an open-source, self-hostable online chat service that offers collaboration options. We use Mattermost mostly for internal communication between employees and partners, and also for long-term clients. 

Our Mattermost server is integrated with other tools such as GitLab (our software workflow), Redmine (our project management tool) and Google Meet (an online meeting platform).