Apple's CEO Steve Jobs promised on Wednesday that the company would release a software development kit for creating third-party applications on the iPhone by February, adding that the need for security has slowed the release.
 The statement appeared on Apple's site as a letter from Jobs to Apple's customers, where he stressed that the company wants native third-party applications running on Apple's mobile device. However, the company refuses to risk adding possible vectors for attack and wants to make sure the iPhone maintains adequate security, Jobs said.
 "This is no easy task," he stated in the letter. "Some claim that viruses and malware are not a problem on mobile phones -- this is simply not true. There have been serious viruses on other mobile phones already, including some that silently spread from phone to phone over the cell network. As our phones become more powerful, these malicious programs will become more dangerous."
 Hardware hackers worldwide worked over the summer to crack the iPhone's protection in order to use the device on carriers besides AT&T or load third-party software onto the system. However, an update to the iPhone froze modified or unlocked devices and reportedly caused problems with some unmodified phones as well, angering users. Apple had warned customers prior to releasing the update, which upgraded the iPhone to version 1.1.1, that the software patch could disable any phone that had been modified.
 Two lawsuits have been filed against Apple following the software upgrade by customers angry at Apple for blocking their hacked iPhones with the company's latest update.