Mastodon, a Destributed, Decentralized Twitter / Weibo Alternative
Official Introduction Site
Source Code
Some existing mirrors, you just need to register and then log in,simply like twitter: (basically official)

Accessable Mastodon in Mainland China: (japan)
It’s mirror: 1 2 3 4
It’s Mirror: 1 2 tg (Blocked)
It’s Mirror: 1 2 (Not accept public registration) (for tech)

Accessable PeerTube instances in China:
(Maybe you should use / in China )

Other Mastodon instances
other peertube instances