BANGALORE, INDIA: When way back in 1999, Salesforce.com founders - Marc Benioff, who was a former Oracle executive, Parker Harris, Dave Moellenhoff, and Frank Dominguez - set out to build their own enterprise cloud, or 'the best that Internet can provide' architecture, they aped the then Web service giant Amazon.com.

This was a place where users do not have to buy hardware or software or even have to run any infrastructure on their premises, as all of these can be availed from the platform called cloud.

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Going forward it also borrowed the concept of multi tenancy, for its own enterprise application, from the likes of Google, Facebook, Yahoo, which scales up and down as required.

“Cloud is similar to an apartment, being shared by several tenants,” notes Chuck Ganapathi, senior vice president, products, Salesforce.com.

Today, after over a decade since its existence, Salesforce.com boasts of about 87,000 'tenants' for its 'apartment' (as on November 2010). Though its largest customer base is in the US, Salesforce.com saw a  42 per cent year-over-year growth in India, which is the highest in Asia Pacific.

A large portion of its service is free for users; however, it also serves over two million paid users. In the third quarter of the financial year, Salesforce.com added 48,000 new customers and during FY2011, the company added approximately 19,800 net new customers.

“We have one system that hosts all of our 87,000 customers; however, the data customization is kept completely separate. This is how we define cloud.”

Now, let's see what comprises Salesforce's cloud architecture.

Salesforce.com has one giant infrastructure in the cloud, called the Salesforce Cloud, and all its platforms are build on this.

“Salesforce.com has all the infrastructure such as hardware, software, network, API, disaster recovery etc, built into it,” says Chuck.

On top of this cloud, Salesforce.com has six other clouds also.

Applications Cloud: This is the underlying Force.com Cloud platform, which is Salesforce.com's platform-as-a-service product. The platform allows external developers to create add-on applications that integrate into the main Salesforce.com application and are hosted on Salesforce.com's infrastructure. It is also called the Custom Cloud.

Sales Cloud: Application that is used by sales people to manage their pipeline to see how the company is doing. The Sales Cloud includes a real-time sales collaborative tool called Chatter, which provides sales representatives with a complete customer profile and account history.

Service Cloud: The Service Cloud provides companies with a call center-like view that enables companies to create and track cases coming in from every channel, and automatically route and escalate what’s important

This manages the post-sale customer application, and the entire lifecycle of customers. This is the fastest growing cloud from the revenue perspective. Here the firm had put into use the technology that it acquired through Extranet.

Data Cloud: This includes Jigsaw, a US company that was acquired last year. It has over 20 million contacts. This manages the data.

Chatter Cloud: Also called, 'The Facebook for enterprise', it is an enterprise collaboration application. Launched in June 2010, Chatter Cloud is very much similar to Facebook and Twitter. This is the fastest growing cloud for Salesforce.com today in terms of number of customers. It has both paid and free versions, and the latter supports more customers than the former. Today there are about 60,000 companies who are using the Chatter Cloud.

Database.com: Is the first Database Cloud. With this Salesforce is opening up the same giant database-as-a-service it already uses to power the Salesforce CRM application itself – and offering a full complement of developer tools and security controls to go with it. Instead of subscribing to Salesforce, here you subscribe to Salesforce's back end.