JustBookmarks – a simple browser-independent bookmark manager
Uses the ancient Netscape HTML format to avoid vendor lock-in and sync headaches.

Social discovery angle is interesting, but Raindrop and Pinboard exist.
Knowledge workers and content curators
Raindrop.io · Pinboard · Diigo
Uses the ancient Netscape HTML format to avoid vendor lock-in and sync headaches.
Bookmarks stored as Markdown in your GitHub Gist, fully client-side.
iCloud-native bookmarks when Raindrop.io and Pocket already dominate this space.
Hybrid search (semantic + keyword) with Reciprocal Rank Fusion, but bookmark managers are solved.
Masonry grid for X bookmarks beats the native list, but manual install kills friction.
Arc's sidebar, but for any browser—local-first, no signup required.