Facebook Chat drops XMPP, as well as Google Hangouts earlier.
Facebook Docs:
"[...] On April 30, 2014, we announced the deprecation of the XMPP Chat API [...] The service and API this document covers will no longer be available after April 30, 2015. [...] We recommend developers who have integrated with the XMPP Chat API deprecate this functionality from their apps before April 30, 2015 to avoid broken experiences. [...]"