XMPP – Myths and Legends
&gt; XMPP is unreliable without a bunch of extensions.<p>and<p>&gt; XMPP typically uses reliable stream transports, so even without extensions it&#x27;s pretty reliable.<p>are really saying the same thing. TCP doesn&#x27;t protect from losing data that&#x27;s been sent but never received due to dropped connections, which in practice happens a lot, especially in the mobile world. That even seems to be acknowledged in the explanation. A more honest answer would just point out the extensions.<p>Apart from that, I agree. Hopefully XMPP in the IM protocol incarnation can reunite the pitiful, broken up messenger world.