Apple will release an SDK (software developers' kit) for the iPhone and iPod touch in February, according to Steve Jobs.
The SDK will allow third-party developers to make native applications for both devices, Jobs said in an open letter posted to the company's website.
Jobs said it would take until February because Apple is trying to provide a platform for developers, but also security for its customers.
"This is no easy task," said Jobs. "Some claim that viruses and malware are not a problem on mobile phones - this is simply not true."
Jobs pointed out that there have been viruses on other phones and networks already and because "the iPhone is the most advanced phone ever, it will be a highly visible target".
"We think a few months of patience now will be rewarded by many years of great third-party applications running on safe and reliable iPhones."
Apple faced some harsh criticism from consumers when it released iPhone Update 1.1.1, disabling all third-party applications on the iPhone.