Steve Jobs has posted another one of his open letters, this time announcing a third party SDK for the iPhone come 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.
It will take until February to release an SDK because we’re trying to do two diametrically opposed things at once—provide an advanced and open platform to developers while at the same time protect iPhone users from viruses, malware, privacy attacks, etc. This is no easy task.
He cites security concerns as the reason for the delay, and hints to the use of digital certificates as a way to prevent malware:
Nokia, for example, is not allowing any applications to be loaded onto some of their newest phones unless they have a digital signature that can be traced back to a known developer. While this makes such a phone less than “totally open,” we believe it is a step in the right direction.