Here at the OERu, we provide a service, attached to all of our online courses (and available to all of our partners - or anyone else for that matter) which allows anyone involved in those courses to communicate with their peers from any one of a dazzling array of online "places" with WikiEducator Notes (aka WEnotes). The entire system is free and open source software (FOSS). 

One of the OERu's most compelling technological capabilities is the set of internally developed open source tools that allow us to automatically transform and inject a collection of MediaWiki content on WikiEducator (usually in form of micro-courses) making up a course into a mobile-friendly, easy-to-navigate WordPress site, usually situated on OERu's Course WordPress Multisite implementation.

Not long ago, Mastodon, an open source, federated alternative to the proprietary network-effect wunderkind, Twitter, came out of no where.

A few months back, I posted instructions on deploying Rocket.Chat and Wekan instances (and their mutual dependency, MongoDB) individually. Since then, I've spent some time with Docker Compose, a set of scripts which help you to define, build, and manage a set of Docker containers. Docker Compose is a thing of beauty. This is the way I now deploy Rocket.Chat, Wekan, and MongoDB together.

Our approach to technology here at the OERu is inspired by the UNIX tool philosophy which can be summarised as follows:

"create simple tools that do one job well, and make it easy to combine them to work together"

At the OERu we have two separate instances of market category leading Discourse Forum: one for OER partner and contributor collaborators and the other for learners. These days, online forums are seen as a bit old-school: fuddy-duddy. From my point of view, however, Discourse is "Forum-NG" (a Next Generation forum).

Mautic is an open source marketing automation web application.

Rocket.Chat is a modern, open source messaging application which is functionally similar to a popular (and heavily marketed) proprietary tool called Slack.

(Update 2017-05-24: see an easier way to run Wekan, Rocketchat, and MongoDB) You may not have all of these installed, but if you're running Wekan or Rocket.Chat based on our instructions, you'll also have MongoDB, and the need to keep them all up-to-date to benefit from their rapid development processes (quick bug fixes and new and improved features every few days!).

Wekan is an excellent, easy-to-use "kanban board" project management support tool, suitable for all manner of projects. For those who have used the highly marketed Trello kanban service, Wekan is functionally similar open source alternative that organisations can host and control for themselves. They can also enhance it in whatever ways they are moved to do so. We encourage our partner institutions to consider this path as a way of reducing costs as well as increasing freedom and privacy.