Charlie Kindel, the man behind Microsoft's Windows Phone efforts, among other projects, announced he's leaving his employer of 21 years to start a new company.
"I'm not ready to disclose details about the new venture but I can say I will be staying in the Seattle area to build it," Kindel said in a post on his personal blog. "It has to do with sports, advertising, mobile, social-networking, and, of course, the cloud."
In a letter to "several thousand old friends and colleagues," also posted on the site, Kindel emphasized his affection for Microsoft and that it's his entrepreneurial spirit that has him headed out the door, not any frustrations with how Windows Phone is proceeding. 
Kindel will be leaving before the fruition of Microsoft's big deal with Nokia, but this is no Rich Green situation. (Unfiltered: Nokia CTO leaving just as things are getting good).
"To the Windows Phone team," Kindel said in the letter, which mostly reads like a yearbook entry of inside jokes, "I may stop using some Microsoft products now that I'm out of here. But not Windows Phone. The BEST product Microsoft has ever built. Do not let up!"
In an interview with GeekWire, Kindel expanded on this theme, praising the growing Windows Phone ecosystem that he says he's leaving in "fantastic hands." While competitors such as RIM have struggled to grow their app offerings, Kindel has helped get Microsoft's numbers climbing. (MDP: Microsoft Offers Kid Gloves to Android Developers Willing to Talk Windows Phone).
"We have close to 27,000 apps in the marketplace, the best toolset and amazingly high customer satisfaction," he told the tech site. "We would not have gotten to the table with Nokia if they didn’t believe we were in the race to win long term. We’re now in the middle phase of the marathon. This is where Microsoft’s stamina genes will come into play."
While Kindel may have an iPad in his future, he insisted he sees the business value in Microsoft beyond his personal allegiance.
"Hypothetically, if my new company were to build mobile apps, we’d target WP7 first," he told GeekWire. "You know the old saying, 'Code Talks'? I know I can build a beautiful and functional WP7 app in a fraction of the time it would take to build an iOS or Android app. Startups are about executing quickly. But I’m sure we’d quickly take what we learned there and apply it on all the popular devices."
Still, allegiances die hard. In his open letter, thanking his children, he added, "Remember, every time you use Google, a puppy dies."
