Here’s an invite link: https://join.slack.com/t/crystallang/shared_invite/zt-dclgignr-K3tiL5mxIjS19PxEaxY64w
EDIT: the invite link expires in 30 days. Up to 2000 people can use that invite link. I think for now this is fine. In one month I can post another link, or we can keep it updated somewhere. But for now this is just an experiment.