Below you will find tools and information that will be helpful to developers

source code to add VBRi header to mp3 file
      For mp3 developers, .tgz file, size: 221 kb

mp3 Surround Detect
      Free Utility to Detect if a file with a .mp3 extension is an mp3 Surround file. (win32 and Linux32)

mp3 VBR Header Software Development Kit
      For mp3 developers, .zip file, size: 3 kb

ACM Encoder Sample Code (mp3 encoding)
      this is a minimal set of source code needed for encoding mp3 files using the
      l3codecp.acm ACM filter driver that is installed along with windows media
      player 10

ACM Decoder Sample Code (mp3 decoding)
      minimal implementation of mp3 decoding to pcm using the already installed
      windows ACM filter driver

spdif Sample Code
      example source code on how to send AC3, DTS and MP3 files directly out the
      spdif port

mp3surround Technical Information
      mp3Surround - Multi-channel MP3 audio coding white papers (pdf file)

mp3PRO Detect
      Free Utility to Detect if a file with a .mp3 extension is an mp3PRO file.
      (win32 and Linux32)

Ensonido Technical Information
      Information regarding the new Ensonido Technology