Zulip's core design goal is to make it effective for complex discussions, and our users tell us that it's working. E.g., cutting-edge math research https://zuli

Zulip's core design goal is to make it effective for complex discussions, and our users tell us that it's working. E.g., cutting-edge math research https://zulip.com/case-studies/lean/ https://zulip.com/case-studies/lean/; Rust language development https://zulip.com/case-studies/rust/ https://zulip.com/case-studies/rust/.