Back in the summer, Salesforce announced the general availability of Salesforce Chatter, the company’s cloud-based enterprise "social collaboration" app and platform, which a representative for the company once called "Facebook for the Enterprise."

In September, the company released Chatter Mobile, and announced Chatter 2, which includes a desktop app. Now, Salesforce has announced Chatter Free, which the company says will accelerate adoption of social collaboration throughout the enterprise.

With Chatter Free, any Salesforce user can invite colleagues to collaborate with Salesforce Chatter. "The industry’s reception of Salesforce Chatter has blown away our expectations," said CEO Marc Benioff. "The fact that more than 60,000 enterprises have deployed Chatter within the first five months is amazing and the Chatter Free social invites are going to take Chatter enterprise-wide."

"With Chatter Free, salesforce.com is using the same social invitation model popularized by Facebook," the company says. "Now any Salesforce user can invite any colleague — even those who aren’t already Salesforce users — to collaborate with Chatter. By its nature, this social invitation creates a network effect, as the pool of Chatter users widens and deepens across a company."

With Chatter, employees can follow documents, people, business processes, and application data. Features of Chatter Free include: profiles, status Updates, realtime feeds, file sharing, groups, filters, invitations, Chatter Mobile, and Chatter Desktop.

Chatter is included for free with all paying user licenses of Salesforce CRM and Force.com. Chatter Free is available to all employees of paying salesforce.com customers.

Also today, Salesforce revealed a new attempt to take on Oracle in the database market with Database.com, which includes a social data model, file storage, user management, authentication, and development tools. In the video above, SoftwareAdvice CEO Don Fornes interviews Salesforce’s Senior Director of Product Marketing Eric Stahl about database.com.