Yes, they run a protocol called FunXMPP. WhatsApp used to be an independent company, and they just used the industry standard and improved it a bit. Moxie (of Signal) then later added something that inspired also XMPP OMEMO e2ee on top of that.
That said… Facebook messenger also used to be XMPP, but they moved to MQTT, and there have been constant rumors that Facebook plans to merge the two. Maybe it will happen with the new multi-device feature that is soon in beta.
Yes. XMPP, the protocol, is just an open standard. If theyve implemented their own version, they can ise any license they want.
If they forked an implementation, on the other hand, there are some limitations depending on the license. But even if the server was forked from GPL code, they dont need to publish the server code.
Yes, they run a protocol called FunXMPP. WhatsApp used to be an independent company, and they just used the industry standard and improved it a bit. Moxie (of Signal) then later added something that inspired also XMPP OMEMO e2ee on top of that.
That said… Facebook messenger also used to be XMPP, but they moved to MQTT, and there have been constant rumors that Facebook plans to merge the two. Maybe it will happen with the new multi-device feature that is soon in beta.
P.S.: Zoom is also XMPP :p
Can they do that and not publish the source code?
Yes. XMPP, the protocol, is just an open standard. If theyve implemented their own version, they can ise any license they want.
If they forked an implementation, on the other hand, there are some limitations depending on the license. But even if the server was forked from GPL code, they dont need to publish the server code.