Salesforce.com plans to introduce what experts say will be the final piece in its transformation from a web-based CRM service to a complete enterprise development environment.

Chief executive Marc Benioff will use his keynote at the Dreamforce 2007 conference in San Francisco today to showcase Visualforce.

The new feature will allow Salesforce.com subscribers to use the company's Apex language to create entirely new interfaces.

"We are giving customers the ability to design any application for any device at any time," Ariel Kelman, senior director of product marketing at Salesforce.com, told vnunet.com.

The ability to create an entirely new interface is key to the Visualforce service because it will allow developers to design interfaces for a number of devices and interfaces.

The service had been limited to Salesforce.com's general interface on a PC screen, but developers will now be able to create interfaces specifically for applications such as kiosks or mobile devices.

"We are seeing a crossover from a company that had delivered a customisation suite into having a developer suite for general development," said Denis Pombriant, managing principal at Beagle Research.

Visualforce will be combined with Salesforce.com's CRM service, Apex programming language and AppExchange marketplace to create an on-demand platform that will be known as Force.com.

"You can think of this as the world's first on-demand application server," explained Kelman.

Salesforce.com hopes to present Force.com as an on-demand alternative to in-house software development suites such as Microsoft's Visual Studio.Net and BEA's WebLogic.

The advantage to Force.com, according to Kelman, is that tasks such as backing up data or maintaining hardware will be done automatically.

"Building applications on the Force.com platform is different because [developers] only have to think about the fun stuff," he explained.

However Pombriant told vnunet.com that Salesforce.com will face a challenge in convincing two groups at once that its on-demand service can be a viable alternative to on-premise applications.

"You have to satisfy the finance department, but you also have to convince the developers that it can do the things they need every day. And some of that might provide a higher bar for Salesforce.com than Microsoft," he said.