[joe_the_user]

Open source, sure. But patent free?

Comment here indicates no:

http://news.ycombinator.com/item?id=3166268

If AAC costs $1/device to implement, who exactly cares that the code is "opened"?

[ootachi]

Two mistakes here:

(1) Apple Lossless, not AAC. Apple is not open-sourcing their AAC decoder, which is part of QuickTime.

(2) The Apache license grants a royalty-free patent license.