Taking a cue from Amazon.com, Sun Microsystems Inc. plans to launch its own "public cloud" service, which will let everyone from big-time corporations to dorm-room entrepreneurs run their businesses on Sun's computers without buying hardware of their own.

Santa Clara, Calif.-based Sun planned to announce the offering Wednesday, in a move that reflects the growing interest in so-called "cloud computing," which is industry jargon for providing computing resources over the Internet.

Traditional data centers hog energy, and stocking them with cutting-edge servers and storage machines is expensive, which explains the appeal of cloud-based services. Some examples range from Web-based e-mail to customer-management programs from Salesforce.com Inc.

Amazon says more than 490,000 people and corporations have signed up for its cloud computing service since it launched in 2006, but some analysts have criticized it as a financial dud. Amazon doesn't break the division's financials, and won't say whether it is profitable.

Sun says its public cloud is just one element of its strategy.

Lew Tucker, chief technology officer for Sun's cloud computing group, said Sun believes there are bigger profits in selling the technology to companies that want to provide cloud services themselves, or to large corporations that want cloud services for its employees but refuse to surrender their most sensitive, proprietary data.

Sun needs a new revenue channel, having seen it become harder and harder to sell new server hardware to corporate customers. Sales in Sun's server division fell $191 million last year to $6.26 billion.