First of all, why shouldn't we trust Facebook to federate and interoperate?
- Facebook originally supported chat using standard XMPP. <https://www.adweek.com/performance-marketing/breaking-facebook-to-launch-jabberxmpp-support/>
- Then they dropped support for XMPP in order to force people to use their chat client. It wasn't enough to require that people have a Facebook account — they walled off access via any third party client. <https://www.omgubuntu.co.uk/2015/04/facebook-chat-api-empathy-pidgin-stop-working>
- Facebook originally supported RSS feeds.
<https://stackoverflow.com/questions/9452359/how-to-get-facebook-page-rss-feed-everyone>
- Then in 2015 they dropped support for RSS feeds.
<https://stackoverflow.com/questions/28204978/facebook-rss-feeds-have-stopped-working>
- Of course, Facebook still support RSS today — as a way to get data *into* Facebook.
<https://www.facebook.com/help/work/420814338383806/>
- Facebook originally supported the open oEmbed standard, which would you to embed posts on your Wordpress site (or other web site). Then they blocked that.
<https://www.searchenginejournal.com/facebook-instagram-drop-support-for-wordpress-embeds/383847/>
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