Apple offers technical FAQs, knowledge base and publicly available documentation files including the MOV file format.

Information about the different parts of MPEG-4 Natural or General Audio (GA) from one of the inventors of these formats, see also their page about MPEG-2 AAC.

Overview of their implementation and contribution to the MPEG-4 standard.

DRM is a world-wide initiative to use analog AM radio for digital sound and services implementing aacPlus at very low bitrates, often mixed up with Digital Rights Management for copy protection.

Publicly available standards from the International Organization for Standardization including MPEG-4 with 14496-5 containing the Audio, Visual and Systems parts.

All available articles and documents from the Journal of Audio Engineering Society with search tool including a CD about coding artifacts.

Patent pool administrator for AAC with FAQs and overviews of royalty fees for commercial implementations.

Forum about audio coding in general with two separate boards for AAC.

Bell Labs' / Lucent Technologies multi-lingual TTS demos and introduction to this coding method.

Company that invented Spectral Band Replication (SBR) and combined it with MP3 (mp3PRO) and AAC (aacPlus or HE AAC).