I think the author of RDF* did initial prototype works with Jena
so I've been thinking... would be really nice to have a custom slack for RDF and related technologies
I don't think there's such thing right now
I found a mattermost for Rdf4J but it seems dead
(https://mattermost.eclipse.org/eclipse/channels/eclipse-rdf4j)
we've implemented rdf* and sparql* in Stardog