Fabian Charles Cook- Lead Software Developer, NZ Digital
Open source, doesn't lock you into anything, complete ownership of data, hosted where ever you want.
We use Rocket.Chat for our clients that want a "slack" like chat within their software,
Adriano Caheté- UX Designer & FrontEnd Developer
It's like a Slack, but it's open source and self hosted. You can start a RC installation fast with a Digital Ocean Droplet.
Open source alternative to Slack
Each year we review the world of open source and recognize top new projects launched during the past year - congratulations to the 2015 Open Source Rookies.
Camunda BPM is as good as it gets in open source BPM and workflow. Originally a fork of Alfresco's Activiti, Camunda has developed into an elegant solution for automating the three pillars of BPM: system processes, human workflow, and case management.