Internet Archive @archive.org Internet Archive is a non-profit research library preserving web pages, books, movies & audio for public access. Explore web history via the Wayback Machine. 
Wikimedia Foundation @wikimediafoundation.org We are the nonprofit organization that hosts Wikipedia and other free knowledge projects. Working to create a world where every human can freely share in the sum of all knowledge.
donate.wikimedia.org
Stockfish @stockfishchess.org Free, open-source, and cross-platform chess engine, trusted by grandmasters and leading chess platforms worldwide.
https://stockfishchess.org/
Lichess @lichess.org https://lichess.org The free chess server. No paywall, no tracking, no ads. Just the good stuff. User support requests should be directed to https://lichess.org/contact
Wikipedia @wikipedia.org A free, collaborative, multilingual internet encyclopedia.
donate.wikipedia25.org
Bluesky @bsky.app official Bluesky account (check username👆)
Bugs, feature requests, feedback: support@bsky.app