Rant of the day: much of the rah-rah coverage of Real's Free-the-iPod campaign has accused Apple of using a "proprietary" file format in iTunes.

Many writers covering this story seem to be unaware of two important facts:

1. Apple's major competitors all use proprietary file formats to copy-protect the songs they sell online.
2. The iPod and iTunes also support other file formats, including MP3 (32 to 320 Kbps), MP3 Variable Bit Rate, AAC (16 to 320 Kbps), WAV, AIFF, Audible, and a new format called Apple Lossless audio (similar to FLAC). Apple does not support Windows Media files.

The fact that most stores use proprietary file formats is disguised by the fact that many online music stores use a copy-protected form of Windows Media -- a file format owned and controlled by Microsoft. These songs can be played using the Windows Media player and any other software that supports the protected WM file format.

RealNetworks sells AAC files wrapped in a copy-protection controlled by Real.

Sony, bless its heart, converts everything to its own ATRAC3 format, and tries to sell songs in a copy-protected format called ATRAC3plus that no one but Sony will ever use.

Technically speaking, even MP3 files are "proprietary" -- Licensing terms are set by Thomson and the Fraunhofer Gesellschaft, the owners of the MP3 patents. (If you want to encode MP3 files in Windows Media Player, you have to buy an "MP3 Creation Pack" plug-in.)

The argument against proprietary formats is a bit of a red herring in the Harmony debate. If you want to take Apple to task for not supporting FLAC or Ogg Vorbis files, I'm all ears, but let's leave the word proprietary out of this particular discussion.