Name this favourites storage service?

I had a service for saving my website favourites, similar to Delicious.

I had an account which i could log in and save them into lists/folders.

It also let me have a Safari extension when i could click and add directly from within Safari.

My Safari crashed though and i lost my extensions and i cannot for the life of my remember what it was called!

All i remember was it started with K (i think)

Any ideas…?