Salesforce.com has launched Force.com Sites, an extension to its cloud platform that lets customers deliver web sites and applications.

The service, which has already been running as a developer preview for six months, is similar to Amazon's EC2 and EMC's Atmos, but ties directly into the company's customer relationship management system as well as other Force.com applications and services.

Companies can use Force.com to build and run applications for internal business processes and public-facing web sites entirely on Salesforce's real-time cloud computing system, thereby removing the need for their own software or hardware infrastructure.

"Force.com Sites dramatically expands Force.com's role in cloud computing for the enterprise," said Marc Benioff, chairman and chief executive of Salesforce.com.

"With Force.com Sites, customers can now run any web site in our cloud. We expect the community to unleash entirely new kinds of applications and innovations that realise our vision of The End of Software."

Tim Barker, senior director of products for Salesforce.com in EMEA, said that businesses now need sites to be dynamic and flexible, but developing and hosting these in house can be slow, expensive and not very scalable.

Force.com Sites is well suited to marketing and promotional online campaigns, according to Barker, as these need to be developed quickly and economically while being able to respond to spikes in traffic and provide a good interface to customer information.

To highlight the strengths of the new system, Barker highlighted the success of a customer preview programme involving 85 companies, from small firms to large multinationals. Launching in February, these sites had over 38 million page views, 350 million site hits and served more than 5TB of data.

Salesforce also today announced that it will be offering a free version of its Force.com subscription.

The Free Edition will allow companies to experiment with and test the building of cloud-based applications and sites for up to 100 users. It includes access to the Force.com platform, one custom application, up to 10 custom objects (custom database tables) per user, a sandbox development environment to test app or site before deployment, free online training and a library of sample applications.

"Now more than ever, companies are asking how they can run their entire businesses in the cloud," added Benioff. "Force.com Free Edition will enable every company to experience success with cloud computing. This will empower anyone to build and run their first cloud computing app for free on Force.com."

All Force.com subscribers will be able to use Force.com Sites for free, up to a point. Those on the Free Edition will get up to 250,000 monthly page views included, while Enterprise Edition customers will get up to 500,000 monthly page views, and the Unlimited Edition includes up to one million monthly page views.

Regardless of edition, each additional million page views is available for $1,000 a month, but all figures are average over a three month period to allow for peaks and troughs.

Customers and partners have built more than 110,000 business applications on Force.com, from manufacturing, finance and supply chain management, to brand management, claims processing and order management, the firm said.