ownCloud is a free and opensource file sync and share app which is self hosted.

XMarks is a cloud based bookmark management platform.

Raindrop.io syncs bookmarks into the cloud and makes them beautiful as well as easy to search.

VisualizeUs helps you collect and connect to the best visual inspiration of the web.

Pearltrees is a visual and collaborative curation tool.

Pocket is a cloud based article snippet and bookmarking platform.

StumbleUpon is a discovery engine that finds and recommends web content to its users.

Fretsi is a social knowledge platform that makes everyone's knowledge public and rewardable.

Jolicloud is a cloud computing with the Jolibook, the first personal cloud computer.

Memotoo sync all your contacts from Gmail, Facebook, phone, Thunderbird, Outlook, etc in a single address book.