An irregular reminder that calling this place "Mastodon" has a bit similar energy as saying "I just sent you a GMail."
"Fediverse" (or "fedi") is a better term.
Mastodon is just one of many software projects that talk to each other to create this multi-instance social network:
https://axbom.com/fediverse/
(kudos to @axbom for this fantastic infographic!)
There are blogs, Reddit-like communities, video instances and many more, all part of fedi.
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All senooken JP Social content and data are available under the Creative Commons Attribution 3.0 license.