Intuit plans to open a QuickBooks app store on Microsoft's cloud platform Azure, the two companies said today.

The app store will allow software developers to make, sell and distribute Web applications that work with QuickBooks, Intuit's bookkeeping software for small businesses.

Intuit first made its partner platform available to developers a year ago, and opened the application center in October. The company declined to give numbers on how much software had been sold through the platform in the past three months. About 40 applications are now available.

Jamin Spitzer, director of platform strategy at Microsoft, said it was significant, "having just launched at PDC [Professional Developers Conference] and still in the very early stages of building out that ecosystem and raising that awareness among users and developers, having a company like Intuit place a bet on Azure."

Microsoft opened Azure to the public in January on a trial basis. In February, the company plans to start charging for the platform. The cloud platform allows developers to build, sell and distribute software through the Web. It's like an iTunes for software.

Alex Chriss, director of the Intuit Partner Platform, said he was excited "to go to those small businesses and say whether its back office or front office or collaboration you've got an application."

Intuit will also make Microsoft Online Services software, such as Sharepoint and Exchange, available in its app store.

The announcement came the same day Microsoft was in Washington, D.C., lobbying for stronger government regulations on cloud computing. Here is our earlier story on that.