Stride is just re-branded HipChat.
As an example, the only way to edit a message is to use a sed-style "s/foo/bar", which is absurd. Because of this, you can't edit messages other than the most recent one, and if you want to edit one instance of "foo" but not another instance of "foo" you're out of luck. That's a terrible piece of UX even if you're in the only subset of users (software devs familiar with sed-style search and replace) where it makes any sense whatsoever
As a sibling comment said, the main reason my team abandoned Hipchat for Slack was Hipchat was hopelessly buggy and unreliable at the time we tried to use it.
HipChat is a terrible name for a work-related collaboration tool, but "Slack" isn't great either....
I guess it is a new major release of HipChat (with re-architecting) and re-branding. Same lead (Steve Goldsmith).
Unless an insider tells, we won't know I guess :)
The more recent offering (Bitbucket Server) falls behind the curve as well, even when compared to their own Bitbucket Cloud service.
Not curious enough to do the kind of blackbox exploration folks at https://webrtchacks.com or other sites do :)
Stride is a brand new product (not a rebrand of Hipchat), we did not repurpose Hipchat's code. It's built from ground up on Atlassian platform - new protocol, clients, platform, etc. One exception is the video bridge technology which remains powered by the Jitsi.org open source product (which we acquired in 2015). I do look after both products (Hipchat Cloud and Stride) for Atlassian, happy to answer questions.
Would have been a shame not to use the Jitsi technology for sure, I deeply respect Emil Ivov and team.