Apple have so far failed to pursue a tough legal stance against Real Networks after the latter, much to the former's annoyance, announced in the summer that it would be selling music in a format compatible with iPods using an unofficial version of Apple's AAC codec. However, Apple's fight against Real is active on the technology front.
The new iPod Photo is the first Apple digital music player which has been made so as to not be compatible with Real's unofficial AAC tracks. This means that music fans who buy tracks from Real's Rhapsody service will not be able to play them on an iPod Photo, despite Real's Harmony system which makes tracks compatible with as many different digital music players as possible.
Real, still pleased that Apple haven't managed to stop their tracks being used on existing iPods, despite various software upgrades, say they will now look to develop their Harmony service so it does output tracks that will play on the iPod Photo. Which presumably means the two companies will be playing cat and mouse technology development for some time to come.