Salesforce.com, Inc. has been expanding beyond its core CRM business for some time, and yesterday took another step in that direction with the acquisition of cloud-based word processing app Quip. The deal was priced at $582 million, according to a filing made with the U.S. Securities and Exchange Commission on Monday.

Quip is a productivity software suite that will be used by Salesforce to expand its offering in word processing and collaborative communications. It works on PCs, but the platform’s real strength is said to be on mobile, with the company boasting that “it shines on phones and tablets”. Quip also makes it easier to visualize collaboration via a highlighted update feed.

This mobile focus is not really a surprise when one considers that Quip co-founder and CEO Bret Taylor helped to create Google Maps, founded the social networking site FriendFeed (which was acquired by Facebook in 2009), and served as Facebook’s CTO during its aggressive mobile expansion phase.

The acquisition effectively gives Salesforce a tool to rival Microsoft Word and Excel, and Google Docs, allowing it to step up its competition with both companies. It’s not clear how much revenues Quip pulls in, but the three-year-old startup claims to have more than a million users, and boasts that “thousands” of teams that have adopted its services. It currently offers two premium versions of its platform (for small companies and large enterprises) at $12 and $25 per user per month, respectively.

Taylor and his fellow Quip co-founder Kevin Gibbs both insisted in a blog post that the platform will continue to grow under Salesforce’s stewardship.

“As part of Salesforce, we will be able to expand our service more quickly and reach millions of people all over the world,” the co-founders wrote. “And, we’ll be able to extend the Salesforce Customer Success Platform in powerful new ways with our next-generation productivity capabilities. The possibilities of mixing data, content and communication are amazing.”