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 ## Matrix
 
-TODO
+All communication during the course will be done via [matrix](https://matrix.org/).
+You can create an account on our own [local server](https://riot.86thumbs.net/) or choose one of the many providers online.
+A *non exhaustive list* can be seen below.
+
+* [nerdsin.space](https://nerdsin.space/#/welcome)
+* [matrix.org](https://app.element.io/)
+* the bxl [hackerspace](https://app.element.io/) offers accounts too
 
 ## Git