If you would have asked me 5 years ago which company, Apple or Microsoft,  would have released a mobile phone that was super popular and got most of its success from a great developer ecosystem of 3rd party applications, I would have said Microsoft in a heartbeat. The reason is that traditionally Apple has been pretty “closed” and Microsoft always relied on 3rd party software developers, like myself, to build compelling applications for its platforms.

The Mac was a “superior” operating system than the early versions of Windows, however, Windows won the battle for supremacy (and still is winning with well over 90% market share). The reason why is that Apple was outright hostile to 3rd party software developers and Microsoft courted them. Building a developer ecosystem is in Microsoft’s DNA and clearly not in Apple’s.

When the iPhone SDK shipped, the tables were turned. Apple is now depending on 3rd party developers for continued success of its iPhone (and iPad). With the most applications, the iPhone is well ahead of the pack. Google’s Android market, with 30,000 apps, is far behind in second and Microsoft Windows Mobile is an also ran.

This week at the Mix conference, Microsoft announced the development platform for Windows Phone 7. Building apps for the new Windows Mobile 7 phone is super easy: Silverlight + Visual Studio is the primary way to do so. Last time I googled, there were about 5 million .NET developers worldwide, so Microsoft gained 5 million developers in the mobile phone wars.

So the question is: Can Microsoft out Microsoft Apple? Being a Microsoft watcher, I know that this is in Microsoft’s DNA and that Apple is a recent convert, so I would say that Microsoft does have a good shot. I would much rather code in Silverlight than Objective-C, the (painful to use) development platform for the iPhone. Let’s take a look:

Pros for Apple:

• Best selling Smartphone on the planet
• Apple “coolness”

Cons for Apple:

• Developer outreach is new to Apple
• Objective-C is not a developer friendly platform

Pros for Microsoft:

• Developer Outreach is in their DNA for 30 years
• Silverlight is an easy to use, modern developer platform that is already popular with 5 million developers

Cons for Microsoft:

• New to the “cool” Smartphone game
• Lack of “cool” credibility with consumers

Where will this all go? Apple certainly has a *huge* head start. Microsoft has its work cut out for it, however, over the last 15 years I have watched Microsoft be counted out before and succeed-they work best when they have their backs against the wall. Let the battle begin!