Basket is an online knowledge management platform.

BibSonomy is a social bookmarking and publication-sharing system.

lumio is an online content organizing platform.

Diigo is a powerful research tool and a knowledge-sharing community.

Fetching is a new kind of bookmarking app.

Instapaper browser extension to save links for offline reading.

BeeCanvas is an online whiteboard based visual collaboration tool.

Bookmark OS is a bookmark manager and organizer.

CherryTree is an hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.

elCurator let you bookmark, read and collaborate with ease.

Google Bookmarks is a free online bookmarking service, available to Google Account holders.

Joplin is an open-source free note taking and to-do application.