Buku - A powerful command-line bookmark manager.
LinkLocker - LinkLocker is a lightweight bookmarking service with an emphasis on privacy.
Shiori Bookmark Manager - Simple bookmark manager built with Go
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Linkman - Linkman Pro allows for managing large amount of URLs in its own database.