IIRC, It was successful for a long time, but then when Google started supporting it, they captured a lot of the market because gmail was so popular, and it had

IIRC, It was successful for a long time, but then when Google started supporting it, they captured a lot of the market because gmail was so popular, and it had xmpp chat support built into it with gchat. Eventually, for various reasons, Google decided that an open xmpp based system didn't work for them, and they closed it and extended it. This was effectively the end of xmpp as a distributed tech that many people use today. Interesting, in a lot of ways SMTP is no longer an open system. It is extremely hard to operate a mail server in such a way that your valid emails get delivered correctly and not marked as spam. So for example in the name of fighting spam, it is extremely difficult to participate in this "open" system.