XMPP was created to provide an open alternative to the proprietary instant messaging systems that popped up in the mid 1990s, but wasn't usable until several ye

XMPP was created to provide an open alternative to the proprietary instant messaging systems that popped up in the mid 1990s, but wasn't usable until several years after several of those had gained significant popularity. I suspect the number of people who tried XMPP and rejected it in favor of something proprietary is tiny in comparison to those who never heard of it. IM may be the first category where an internet application first appeared in a modern, user-friendly, full-featured form in a proprietary implementation before there was a standardized implementation.