Floccus Bookmarks Syncβ β β β β Very flexible, syncs across many different desktop browsers and mobile devices, and for privacy it can run on your own server or encrypted on another cloud service.
Mastodon β Simplified Federationβ β β β β A Firefox add-on that automatically opens remote Mastodon users or posts in your home server when you interact with them.
Wayback Machine Browser Extensionβ β β β βUseful for when you want to make sure the pages youβre reading will still be around in some form in the future, and to easily get at additional context. Checks every page you view against the Wayback Machine, so turn it off when youβre not using it.
Xmarks (Discontinued)β β β β βXmarks was a cross-browser bookmark sync service that I used for a long time to keep Chrome, Firefox, IE, and Safari on multiple computers using the same set of bookmarks. It shut down in 2018.