I see people downvoting this, but while it may not be artfully phrased it's absolutely true. There are countless small projects which fell by the wayside becaus

I see people downvoting this, but while it may not be artfully phrased it's absolutely true. There are countless small projects which fell by the wayside because they didn't get enough users to build a true community (e.g., "Ted," a "Rich Text Processor" that was, about 20 years ago, my favorite WYSIWYG-ish open source word processor) -- and even some relatively big name ones that were created by one company that just didn't get traction when the company stopped supporting them. Google Wave was already mentioned in the comments on this artlce and it counts; another one was the company I was at in the mid-2010s: RethinkDB. AFAIK, there's only been one minor release since the company folded and I think that release was the one that was "in progress" when the doors shut. Zulip seems like it's in a much better place to survive, taking the word of the article, with an active development community around it. (I don't think I've actually heard of Zulip after the original company was bought by Dropbox, although "whether chipotle_coyote has heard of this" is admittedly not a leading indicator of success.)