Apple has announced today that they will be supporting native, third party applications on the iPhone, and that they will be bringing out an SDK in February.

Let me just say it: We want native third party applications on the iPhone, and we plan to have an SDK in developers’ hands in February. We are excited about creating a vibrant third party developer community around the iPhone and enabling hundreds of new applications for our users.

The letter from Steve Jobs stresses that they want to strike a balance between offering an ‘advanced and open’ platform, while still ensuring a secure and stable iPhone.

There are no details as yet on how third party apps may get ‘approved’ or distributed for iPhone, but there is a mention that Nokia’s policy (of only allowing programs that carry a traceable digital signature) is viewed as a step in the right direction.

You have to wonder why Apple took so long to announce this, unless it is genuinely a change of heart / mindset due to all the bad reaction to the platform being (officially) closed up to now.

For me, the reasons really don’t matter too much now. This is great news for anyone who owns an iPhone, or even many of those considering buying one.

I firmly believe that applications make the platform, and as long as Apple gets the details right, this should help foster the sort of rich and broad array of applications that the iPhone platform deserves. There’s already a great community of iPhone developers out there producing some very cool apps – with official support from Apple this community should really take off.