While Rightscale has emerged as a leading manager of underlying cloud infrastructures, MuleSoft is a leading player in a second category of companies: Those helping apps talk with other apps. MuleSoft helps companies integreate SaaS apps so that they work well together, whether they run hosted offsite or behind the firewall.

MuleSoft calls its service an integration-platform-as-a-service (iPaaS) and branded its product CloudHub.

CloudHub enables companies do things like run, Intuit,, Amazon, Twitter, and Facebook together, making sure that changes in one app are reflected in all of the other applications as they happen in real time. CloudHub boasts more than 120 prebuilt connectors for apps, which also include Amazon S3, Gmail, Hadoop HDFS, Magento, PayPal, and Twilio.

MuleSoft CEO Greg Schott says businesses spend about $500 billion dollars every year doing customized work on point-to-point app integrations to make them work to meet IT security, compliance, and performance needs. And apps connections are exploding, as mobile and SaaS apps take hold and public APIs begin to hit the thousands.

MuleSoft competes against the likes of Tibco, a much bigger player that so far has focused mainly on application integration for the enterprise. However, Tibco has recently been building out its cloud offering, including announcing Tibco Cloud Bus last month. MuleSoft also competes against a host of other players focused more on the cloud, including Zapier, Cloudwork, Dell Boomi, and Snaplogic.

Schott doesn’t provide specific guidance on the company’s revenue momentum, but he told VentureBeat the company’s revenue will double this year after more than doubling last year.

MuleSoft also has an interesting business model. It bills up to eight-figure contracts for enterprise companies for help on complex app integration. In other cases, MuleSoft helps integrate a single SaaS app for an enterprise customer and charges based on a percentage markup on the overall contract value. This might be sold at 15 cents on the contract’s dollar value. For example, if a SaaS contract runs for $100,000 a year, a customer may end up paying $115,000 to include integration from MuleSoft, with the $15,000 being kicked back to MuleSoft.

The company has raised $37 million from NEA and Salesforce.

If you’ve used MuleSoft’s product, please let us know what you think, and get our free full report when it is released next month.