Client side data cache

Anybody using a client side persistence object to cache large data sets?

I have found PersistJS, Google Gears and Dojo Storage as the big ones. All javascript based though.

I need to display large datasets as graphs. Live.  Sending updates of the entire data set would be ludicrous.

Maybe I need to think about porting one to ruby?

Scott

http://pablotron.org/software/persist-js/

http://code.google.com/apis/gears/api_summary.html

http://dojotoolkit.org/node/115

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