In recent years, companies have started to use technology called virtualization, which can let one physical server computer act as several. That cuts costs for hardware, energy use and the labor needed to oversee large data centers.
Cloud computing systems build on that trend. Instead of having to own and operate all those servers, companies can choose to outsource data center management. The companies can store data and give employees access to software over the Internet. And these systems can automatically ramp up or scale down the computing resources they devote to any one program, depending on demand.
Microsoft said Monday that PC makers Dell Inc., Hewlett-Packard Co. and Japan's Fujitsu have set up what Microsoft is calling Azure appliances, or networks of servers in their own data centers running Azure. Now the PC makers, which also do technology consulting, can add cloud computing to their menu of services.
EBay Inc. said it would be one of the first customers to use the Azure platform, in two of its data centers. It has already tried out the system, specifically for its page of iPad auction listings.
Some companies, government agencies and others have shied away from putting programs and data "in the cloud" because of security concerns. Having a company such as Dell or HP operate the cloud could help ease their worries.
Microsoft and the PC makers are also working on a version of the Azure appliance that the PC makers can install in end customers' own data centers.
The announcement was made during Microsoft's annual partner conference, held this year in Washington, D.C.