and the reason it works so well is because gchat is based on xmpp which makes it more open to interoperability and access to pre-made libraries etc. And you can use any clients supporting xmpp.
management at google must have decided that interoperability is a weakness and killed it.
Look at my comment above. Yes, at the time XMPP interoperability at the edges seemed like a good idea, but XMPP wasn't a good standard.
No, the reason it worked well was because Google made their own backend that could actually scale and which wasn't based on XMPP at all. (I actually spent a lot of time reading the code and talking to the people who designed Talk while I was at Google, because that project had a lot of really good lessons in how to deal with challenges in distributed systems).
The XMPP interop was nice, but it was just that: a client interface adapter. I can't think of a single XMPP backend that even comes close to working as well as the custom architecture Google used for Talk.
Actually, XMPP is the worst kind of standard you can have. Something that superficially looks like a good solution, but doesn't lend itself to clear, correct and performant implementation. And at the same time is seen as THE standard for chat. So people won't be inclined to "start over".
But if we're going to have chat interop, that's what we have to do. I'm not kidding.
If XMPP was any good you would see companies that do chat products at scale prefer it, at least in the backend. Imagine all the time you can save. But they mostly don't. Ask people who develop chat systems why not. (Zoom is the only company that comes to mind, but chat isn't the main focus of that product, just an aside)
Google killed XMPP interop because it was a pain in the ass and a technical obstacle. And then chat gradually became a closed affair because we, the developer community, just didn't come up with something that worked well enough to replace XMPP.
> Google killed XMPP interop because it was a pain in the ass and a technical obstacle.
Yet Talk/XMPP was, tied with Hangouts, Google's longest-lived chat system to date (officially, anyway - last I knew a few weeks ago, it was still accepting XMPP client connections).
XMPP has an open and diverse community, and I assure you there are many competent server developers involved in its development.
Disclaimer, I'm heavily involved in XMPP, though I wasn't around for its conception. I've implemented it from both a client and server perspective. I'm not here to claim XMPP is perfect, but it's absolutely a good fit for its problem domain (an interoperable messaging standard).
As a software engineer I've implemented many other protocols too. I assure you that all protocols have their quirks, XMPP included, but I've yet to see anything that would be a suitable replacement.
I blame Google's culture as an organization for their inability to succeed at messaging. I blame financial incentives for large companies choosing to build silos rather than interoperate/federate. Whether that uses XMPP or not I really don't care - all the big players have had plenty of time to propose an alternative (or participate in XMPP development, as Google did for a period). I think only regulation can save us at this point.
management at google must have decided that interoperability is a weakness and killed it.