I didn't know Spectrum until today. It looks similar to Gitter. As I understand it, it means we now have at least three “slack-like”, well-backed, open-source, community-centered chats: - Gitter, now owned by GitLab; - Spectrum, now owned by GitHub; - Mattermost, independent, but fully integrated within GitLab. That's great to have credible alternatives to the proprietary behemots that are Slack, Discord and others,…
Riot is being deployed as the govt chat infrastructure for 5 million users in France.
The SaaS version is modular.im (much cheaper than slack)