LinkLocker - LinkLocker is a lightweight bookmarking service with an emphasis on privacy.
Linkman - Linkman Pro allows for managing large amount of URLs in its own database.
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
LinkStash - LinkStash is an outstanding bookmarks/favorites manager that works with Internet Explorer, Firefox...
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Rons WebLynx - Rons WebLynx is a powerful windows desktop bookmark manager to organize large numbers of websites links. Store bookmarks in folders, tag, edit, rate and much more.