IBM is trying to rally support for an online applications marketplace for small and mid-sized businesses that it plans to launch later this year.

On Thursday, it outlined plans to create the Global Applications Marketplace, where small businesses will be able to browse and purchase applications from potentially thousands of ISVs (independent software vendors) around the world, which local IBM channel partners will then install and manage for them.

IBM optimistically compared the marketplace to Amazon.com, because customers will be able to read reviews of products written by other customers. It will also be like iTunes, in the sense that it will be tied to the vendor's hardware: customers who use the marketplace will have to have an IBM server, just as iTunes customers need an iPod.

The goal is to make it easier for companies with small or nonexistent IT departments to adopt new software and services to help run their businesses. For IBM and its partners it's a way to generate more business from companies with up to 500 employees, a market largely untapped by IBM thus far.

The initiative, also called the Blue Business Platform, was announced Thursday at IBM's Business Partner Leadership Conference in Los Angeles, where IBM pitched the idea to resellers and ISVs. Competitors will include Microsoft's Small Business Center, Salesforce.com and, eventually, SAP's Business ByDesign.

Small businesses will be able to search for applications at the marketplace and enter parameters like the number of employees they have. The system will spit back recommendations, including any IBM infrastructure software that might be appropriate. When the customer decides on an order, IBM sends it to a local reseller who will deploy and manage the software, said Matthew Friedman, vice president of marketing for IBM's Business Systems Division

Success will depend on getting buy-in from ISVs and resellers. To take part, ISVs will have to adopt a set of APIs (application programming interfaces) that allow them to list their software on the marketplace. Other APIs will support remote management capabilities, like the ability to add and remove users or deliver patches, and also allow for integration with other applications and services.

A reseller could connect an application to Amazon's S3 hosted storage service, for example, but only if Amazon chooses to adopt the APIs, Friedman said. Longer term, IBM plans to release other APIs that allow for integration at the data level, allowing resellers to set up business processes, he said.

Only about 10 ISVs have implemented the APIs today, Friedman said, but IBM expects to get many more. Vendors that signalled support Thursday include CFXWorks, which provides credit card processing for retailers; Cincom, which offers a business intelligence product; and InterNetworX, which sells enterprise resource planning software.