The company first disclosed plans for the new platform for its hosted software business last August. The updated infrastructure will include a new data center on the East Coast and two on the West Coast. The so-called Mirrorforce system will have replication capability, so that when one center goes down, another can immediately take over.

Mirrorforce is due to go live this winter, said Bruce Francis, chief strategist at San Francisco-based Salesforce.com. "When complete, it will enable virtually instant disaster-recovery fail-over that should help keep our customers online in the event of a natural or man-made disaster," he said.

The system was upgraded to accommodate the new AppExchange system, which will host hundreds of applications written by Salesforce.com and its partners, Francis said.

"We assessed what we would need to deliver those benefits and continue to scale ahead of our customer needs, and Mirrorforce is the answer," he said.

Salesforce.com CEO Marc Benioff said he is confident that the back-end infrastructure will be strong enough to support the myriad hosted applications the company plans to offer through AppExchange.