Chalk alternatives

I have been using Zulip only for three months, but I can't help wondering how I managed to get anything done without it. Everything about this chat is so thought through that I consider it essential to stay productive. Organizing all conversations into streams and topics makes it clear what each discussion is all about, so you can always mute everything that's irrelevant to you at the moment, and focus on important things. I didn't initially appreciate the full-text search, but now I regularly use it to find all the places where a particular subject was discussed. It's almost impossible to lose something with Zulip.

In addition to that, Zulip for macOS is a total eye candy. I like the minimalistic design, the colors, everything about it! I couldn't have wished for a better app. I also have Zulip for iOS, but I don't use it as much. I think it's kind of difficult to take advantage of all the great Zulip features on a small screen.