Channel Insider content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More.

Microsoft executive Charlie Kindel is leaving the company after 21 years. As general manager for Windows Phone’s developer ecosystem, he played a key role in the development of Windows Phone, which represents Microsoft s best hope for re-establishing a presence in the ultra-competitive smartphone market.

Kindel s is apparently heading to a startup, although an Aug. 8 posting on his personal blog was light on details. “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, he wrote. It has to do with sports, advertising, mobile, social-networking, and, of course, the cloud.”

In an email to friends and colleagues, also reprinted in that posting, he added that Windows Phone is the BEST product that Microsoft has ever built.

Windows Phone has attracted some strong reviews from the tech community, but its marketplace viability remains somewhat in doubt. Research firm comScore is estimating Microsoft’ s smartphone market share declined from 7.5 percent to 5.8 percent for the three-month period ending in June. That included both Windows Phone and the company’ s more antiquated Windows Mobile platform, which is being phased out.

Microsoft hasn’ t yet offered sales figures for Windows Phone, but outside estimates aren’ t rosy. Recently, the Seattle Post-Intelligencer guessed Microsoft s possible revenue from Windows Phone at less than $613 million. That figure came from subtracting Xbox 360-related revenue some $8.103 billion from that of its overall Entertainment and Devices Division, leaving $613 million split between Windows Phone and a variety of much smaller projects such as Zune and Surface.

Microsoft hopes its upcoming Mango update, due to final release sometime this fall, will spur greater consumer adoption. Samsung, HTC, LG Electronics and Nokia have all committed to building new Windows Phone devices preloaded with Mango, along with Acer and ZTE. Some 500 new elements to the update include expanded functionality for the Xbox Live and Office hubs, new multitasking abilities and Bing deeply baked into the user interface.

Whether consumers gravitate to Mango, though, Windows Phone faces substantial competition in the months ahead from Apple s iPhone and the growing ranks of Google Android devices. Apple is widely expected to release its next-generation iPhone 5 in either September or October. 

To read the original eWeek article, click here: Microsoft Windows Phone Executive Departing