Is there a modern sessionStorage alternative that works across subdomains?

Question

We recently switched from cookies to using sessionStorage - the trigger for switching was IE issues.

Now, we're discovering that sessionStorage doesn't work across sub-domains - the storage of www.site.com is isolated from that of site.com.

Is there a modern alternative to get the two to cooperate? This is easily accomplished by cookies, but I'd hate to revert from sessionStorage, or (gasp) use both methods concurrently.

Answer 1

This is almost a hack, and its not secure but it's a neat trick never the less. JavaScript object window.name can hold strings of data and the data does persist even when loading a new page or switching domains. Check this SO about it here:

Using window.name as a local data cache in web browsers