Zulip
Zulip is an open source chat and collaborative software created by Jeff Arnold, Waseem Daher, Jessica McKellar, and Tim Abbott in 2012. Today, it is one of the free and open source alternatives to Slack, with over 60,000 commits contributed by over 1000 people.
Here it’s important to differentiate and it’s not so easy to label Zulip as fully trade-free. 1. https://zulip.com/ is NOT trade-free. There are plans that one can subscribe to in the “cloud”: https://zulip.com/plans/#cloud and even in self-hosted version: https://zulip.com/plans/#self-hosted 2. However, there is a “free-community-plan” for certain groups of people (in education or non-profit for example): https://zulip.com/help/self-hosted-billing#free-community-plan
És per això que es podria etiquetar Zulip com a lliure de comerç per a "Projectes de codi obert, Recerca en un entorn acadèmic, com ara grups de recerca, col·laboracions interinstitucionals, etc., Organitzacions gestionades per educadors individuals, com un professor que imparteix una o més classes, Organitzacions sense ànim de lucre sense personal remunerat o Comunitats i organitzacions personals". Potser 3 blocs poden ser adequats per a això?