Apple Chief Executive Steve Jobs holds the new iPhone at the Apple store in central London, September 18 2007.

BEIJING, March 6 (Xinhuanet) -- Following Steve Jobs' promise to open the zealously guarded inner workings of iPhones to computer programs made by outsiders, Apple will unveil a "software roadmap" for outside developers interested in making programs for iPhones, media reported Thursday.

Apple is expected to make iPhones more compatible with business applications, such as receiving email "pushed" from company servers, in a move that would challenge BlackBerry devices made by Research In Motion.

Apple wants to let developers tinker with iPhone software while simultaneously protecting against viruses and other malicious code.

Jobs is on record saying he expects iPhones to be "a highly visible target" for malevolent software wizards.

Applications made for iPhones should also work on the new iPod Touch, which is essentially an iPhone without the mobile phone feature.

Jobs said Apple might take a lesson from Nokia, which is not allowing outside applications onto some of their new mobile telephone models unless the software has a "digital signature" from a known developer.

Hackers began prying open iPhones to insert custom applications, and break the exclusive service tie between the devices and telecom giant AT&T, shortly after the mobile phones made their US debut in June of last year.