SemanticScuttle

SemanticScuttle is a self-hosted and web-based social bookmarking tool experimenting with new features like structured tags and collaborative descriptions of tags. Originally a fork of Scuttle , it has overtaken its ancestor in stability, features and usability.
Self-hosted and web-based social bookmark manager.

Features

LDAP/Active Directory authentication
RSS feed support: global feed, user feeds, per-tag feeds, private feeds
Public and private bookmarks
Delicious and Browser bookmark import
Theming support
Firefox plugin