Zulip 1.8: Free software Slack alternative with email-style threading

How is threading done right exactly as compared to Slack (I don't use threading)?

Threading done right or wrong in in slack doesn’t really matter. What matters is if your point gets across. Sometimes that’s fine via threads. Sometimes threads get in the way.

We used Zulip (then a commercial product) at FoundationDB, and really liked it. We had teams in two cities.

The threading, which they sell as the core feature, is nice, and does make it more usable for "important" conversations than purely chronological chat. It also makes it easier to screen out conversations you don't care about.

But IMO the killer feature is the "all messages" view that merges chosen streams in more or less chronological order. It makes it much easier to keep up with what you care about asynchronously without throwing everything into a single stream. And therefore it is easier to put down, and to use notifications very selectively, which mitigates some of the major downsides of company chat.

I haven't used Slack recently either, but as I understand it its "all unreads" feature is much clunkier.

I haven't used a recent version, but I would definitely consider using it again.

I was really interested in this.

The first intriguing thing I found was this product is owned by Dropbox.

Slack eating into Dropbox's territory with (decent) file sharing / searching and Dropbox countering with a alternative chat/ threading app is a nice battle.

Off topic, but man I wish FoundationDB hadn't disappeared.