What’s the next killer financial app? No one knows for sure, but the smart money is on it being built for platforms with lots of customers and many banking clients.

Intuit qualifies.

For the first time in its history, Intuit, maker of both consumer financial products and core banking software, will open the APIs (application programming interfaces) to its financial data service and allow third-party developers to use its capabilities to build innovative new software, the company announced today.

“You never know where the next great idea will come from, but we intend to find out. By reaching out to the developer community, we can help identify and solve important customer problems,” said Brad  Smith, Intuit president and CEO.

Some of our readers might recall that Facebook kicked off its meteoric rise by opening its API back in 2007.

Intuit is betting that this invitation for third-party developers to build products based on its data management capabilities — something PayPal has already done — will produce some great products. To that end it has opened up the Intuit Partner Platform as a way for developers outside the Intuit ecosystem to engage with its data and data management capabilities. The first API-driven products have already been released. SaveUp, a free rewards program, test-drove Intuit’s data services to aggregate user data from its users and reported great success. Intuit met with developers two years ago and picked SaveUp and a few other services out of a handful of developers to pilot this program. Another group will be chosen in October and the APIs will be open for all developers in December. Intuit can also benefit from the culture of innovation as developers build products and share ideas. The apps will not all be PFMs and reward programs such as SaveUp for your smartphone. Some will be software designed for use by banks in order to serve  their customers. Keep an eye on the Intuit App Center for the results of this interaction.

“Access to reliable financial data is among the biggest challenges developers face when working to innovate,” said Aaron Patzer, founder of Mint.com, which is owned by Intuit.

Intuit’s products touch millions of lives. In addition to producing consumer financial products Quicken, Quickbooks, and TurboTax, as well as servies like Mint, all of which cumulatively serve more than 60 million customers, Intuit provides financial service technology to more than 1,250 banks and credit unions, allowing customers to securely connect with their accounts and manage their money. These two aspects of Intuit’s business might seem to be only tenuously connected. Neeraj Joshi, Product Manager for Intuit Financial Services, tells Bank Innovation that the Intuit Partner Platform is a “huge step toward creating a connected ecosystem” of Intuit offerings.