Sure, Facebook has picked up new technology through acquisitions, but the social networking company also has a long history of building its own tools. A Facebook executive has revealed another product the company’s engineers have hacked together on their own: custom software for tracking leads.

“We have our own internal [customer relationship management] software,” Facebook chief information officer Timothy Campos told the Wall Street Journal in an interview published yesterday.

In addition to deploying data center equipment built for its needs, Facebook has built and used a wide variety of custom software, including the Hive data-warehousing tool (which has since become available under an open-source license), the Presto querying engine (also now available under an open-source license), the Scuba analytics tool, and an Android code debugging tool, Stetho, among others.

But this latest customization initiative could be a wakeup call to enterprise software powerhouse Salesforce, a vendor of the popular CRM software, Sales Cloud. A customer case study on Salesforce’s website suggests that Facebook is a current Sales Cloud customer. There’s even a blurb from Campos. “Salesforce helps us make the world more open and connected,” he’s quoted as saying.

The page says, “Facebook uses Sales Cloud to manage ad sales and keep track of advertisers’ contact and account information.”

The Facebook-built software appears to have a related purpose. Here’s Campos describing its function in the Wall Street Journal article:

When an advertiser reaches out to Facebook to say they are having trouble with an ad, we have all the information about this company. We can see what other issues they have. For example, if someone’s credit card is about to expire, we know we are going to have another issue next week. We can inform the customer and deal with the issue right away.

So which is it — Facebook’s internal CRM or Sales Cloud? Both, basically. Facebook has no plans to stop using Salesforce at this time, a Facebook spokeswoman told VentureBeat in an email.

Meanwhile, Facebook has quietly also built finance and human resources software on its own, the spokeswoman told VentureBeat.