This working group of the standardization organization deals with codecs like enhanced aacPlus or AMR-WB+ used in mobile telecommunication.

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

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

ARL is a commercial laboratory involved in subjective quality assessment methods like preparing and analyzing codec comparisons for 3GPP.

The open source project FAAC includes an AAC encoder and decoder (FAAD2) with source code packages, developer mailing list, knowledge base, news section and user forum.

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

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.

"Selected advances in audio compression and compressed domain processing", comprehensive overview of internet and mobile communication codecs and new methods for improvement.

Besides this forum for audio codecs there are others for container formats and video encoding in general with FAQs.

"Meeting MPEG-4 advanced audio coding requirements", knowledgeable article summarizing the most important properties of AAC for hardware playback.

Comprehensive guides about DivX, XviD and MPEG4IP, a forum and other resources about digital audio/video coding and streaming.

The old Audiocoding.com forum is still available providing valuable content like FAAC compiling issues with its search tool.

AT&T Labs develops a computer human interface using 2D and 3D talking head-and-shoulder models driven by a Text-To-Speech synthesizer (TTS).

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.

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

Active forum topics in AAC - General and AAC - Tech as well as in MPEG4 Discussion.

Overview of their implementation and contribution to the MPEG-4 standard, especially for the Systems part.

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

Reading list for an MIT seminar, most of the mentioned publications are directly available on their web server or linked to Amazon's book section.

Hard- and software company for professional broadcasting products with AAC/MP4 support.

Reviews, articles and forum discussions about cell phones capable of AAC/MP4/3GP playback (also called "iTunes" format sometimes, use the site search).

John Lazarro and John Wawrzynek from the CS Division, UC Berkeley provide tutorials, downloads, manuals and links related to the Structured Audio format.

The web archive of the public MPEG Industry Forum mailing list with many knowledgeable participants from companies like FhG, Apple and Microsoft.

Official site of this MPEG subgroup with FAQs for the different standards, publicly available reference documents and software.

Patent pool administrator for the MPEG-4 Systems part of the standard including the MP4 file format.

Technical information and developer resources from the Machine Listening Group at the MIT Media Laboratory, the official homepage for this format maintained by Eric Scheirer.

Resource for news, information and products about MPEG-4, H.264, Windows Media, High-Definition, Streaming Media and related technologies.

Upcoming MPEG-4 and Streaming Media related calendar of events.

The latest headlines about MPEG-4, Windows Media, Streaming Media and related technologies.

Announcements of new products from companies or events from organizations related to MPEG-4 and other technologies.

New sources of information like web sites, documentation or tests for MPEG-4 and related technologies.

Platform to support the implementation of their software SDKs including AAC/MP4.

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

Provides public group comparisons of several AAC codecs and other formats at different bitrates.

The writer of AudioMulch, free soundsynthesis software, offers a SAOL/SASL reference guide and decoder resources.

Many TTS demos in several languages from different systems with links to their homepages.

The main goal of the SAOG was to implement Structured Audio (SA) in open source applications offering a portal for their users with forum and downloads of samples and software.

Hardware manufacturer of the Zephyr ISDN codecs for radio and television broadcasters providing articles and brochures about different AAC implementations.

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

List of internet radio stations using aacPlus for their low bitrate streams, among them SomaFM.com and Boomer Radio.

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