just stumbled onto FreeTube
it's an open-source desktop YouTube client that lets you use YT without ads, tracking, etc. i think it uses Invidious as its backend and there are browser plugins that can redirect YT links to open in your desktop FT client. cool so far.
Cybrespace is an instance of Mastodon, a social network based on open web protocols and free, open-source software. It is decentralized like e-mail.