Microsoft released the final version of its Windows Phone Developer Tools late last week, paving the way for developers to submit the first Windows Phone 7 (WP7) apps at the beginning of October. The firm has also released a list of policy guidelines for new Marketplace apps – which appear to take a hardline on pornographic and violent content – and revealed some of the first high-profile apps expected to be available at launch. 

Although there has been over 300,000 downloads of the beta version of the tools, Microsoft’s Brandon Watson said in a blog post that “any application built with a previous version of the tools will fail application certification in the Marketplace.” He urged developers to therefore download the new version, which is available initially in English but expected to be available in French, Italian, German and Spanish language versions in the next couple of weeks. Apps submitted using the tools will take around about five days to pass or fail certification, Watson said. A separate WP7 toolkit for Microsoft’s Silverlight technology has also been made available.

Watson noted that “some of the biggest names in apps and games are working to bring the right mix of high quality content to Windows Phone 7.” Apps running on the platform from the likes of Twitter, Netflix, OpenTable, Flixster and Travelocity were showcased at a Microsoft event last week.

Meanwhile, Microsoft’s newly-published Windows Phone 7 Marketplace policies appear to suggest that the firm is taking a leaf out of Apple’s book by having a strict set of guidelines governing what types of apps it will allow on its new platform. The document lists an extensive list of the types of sexual and violent content prohibited. Interestingly, depictions of other devices are also out of bounds; the rules state that “if an application depicts any mobile or wired telephone, handheld PDA or any other data and voice communicator, it must be either generic or a Windows Phone device.”

Watson notes in his blog that “OEMs and mobile operators have begun final testing of their [WP7] handsets.” However, Microsoft has still yet to set a firm launch date for the unveiling of the first commercial WP7-based devices, which are promised to appear before year-end.