Microsoft has released its developer tools for Windows Phone 7, kicking off the race for third parties to finish their apps in time for the mobile system's launch in a few weeks.
However, for developers who have had their heads down working on code, Microsoft (NASDAQ: MSFT) has one caveat. Any developers writing apps using the beta versions of the tools will need to uninstall the betas and install the final tools, or they will fail certification for Microsoft's Marketplace, company officials said.
"The Windows Phone Developer Tools have gone final, and we have released to the Web," Brandon Watson, director for Windows Phone 7, said in a post to the Windows Phone Developer Blog Thursday.
"Any application built with a previous version of the tools will fail application certification in the Marketplace," Watson added.
The Marketplace is set to open in "early October," he said, adding more fuel to the rumors that circulated last week that Windows Phone 7 will formally launch on Oct. 11.
The current release of the tools only supports English, though, the company says it will release French, Italian, German and Spanish versions in the next few weeks. Applications for Marketplace certification should take about five days from submission to approve or decline, he said.
The Windows Phone Developer Tools are available for download here.
Wednesday evening, Microsoft held a small gathering in Seattle to show off some of the Windows Phone 7 apps that are nearly finished. Those included demos of apps for Twitter, Netflix, OpenTable, Flixster and Travelocity, Watson said.
Microsoft began beta testing the Windows Phone Developer Tools in mid-July. A week later, the company began distributing engineering test copies to thousands of developers it hopes will write Windows Phone 7 apps.
By late August, the company reported that the beta developer tools had been downloaded some 300,000 times.
In early September, Microsoft announced that its work on Windows Phone 7 was virtually done and that it had been "released to manufacturing," meaning that the code had been handed off to device makers for final testing and integration into phones that will go on sale by the time the holiday shopping season begins this fall.
The final package provides all of the developers' tools as a single download, Watson said. They include Visual Studio 2010 Express for Windows Phone, the Windows Phone Emulator, Expression Blend 4 for Windows Phone and XNA Game Studio 4.0. The tools also feature a smart installer that only downloads what the developer needs.
"The tools will work with your existing Visual Studio 2010 and Expression Blend 4 installations," Watson added.
Microsoft has made a big bet with Windows Phone 7, and one key to its success or failure is whether there are enough apps and games to make it at least seem as if it may grow to be competitive with Apple's (NASDAQ: AAPL) App Store.
To that end, in July Microsoft confirmed that it has been paying some third-party developers to write apps and games for Windows Phone 7.
However, it doesn't stop there.
In late August, a stock analyst told InternetNews.com that Microsoft not only will spend as much as $400 million to promote the launch of the phones, but also the combined spending by Microsoft, its hardware vendor partners, and software publishers overall is likely to run into the "billions" for the launch.
Microsoft has declined to say when it will hold the launch event for Windows Phone 7.