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
feelDweb Online - feelDweb is an online social bookmark manager that allows you to organize webs and searches easily...
Sitebar - SiteBar is an Online Bookmark Manager.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
LinkLocker - LinkLocker is a lightweight bookmarking service with an emphasis on privacy.