If you want to be specific - and for legal reasons, he does - Johansen has reverse-engineered FairPlay, the encryption technology Apple (Charts) uses to make the iPod a closed system. Right now, thanks to FairPlay, the songs Apple sells at its iTunes store cannot easily be played on other devices, and copy-protected songs purchased from other sites will not play on the iPod. (The iPod will play MP3 files, which do not have any copy protection, but major labels don' t sell music in that format.)

Johansen has written programs that get around those restrictions: one that would let other companies sell copy-protected songs that play on the iPod, and another that would let other devices play iTunes songs. Starting this fall, his new company, DoubleTwist, will license them to anyone who wants to get into the digital-music business - and doesn' t mind getting hate mail from Cupertino.