Sources

If you're looking for places to pull either file format information, or to verify stuff you've found, or to go that extra mile to track down variations, here's some similar endeavors and items.

List of Places Keeping Track of Formats

 * http://archivematica.org/preservation
 * http://www.fileformat.info/
 * http://www.ace.net.nz/tech/TechFileFormat.html
 * http://wotsit.org/ (presently broken)
 * http://unarchiver.c3.cx/formats
 * http://www.nationalarchives.gov.uk/PRONOM/ Version-level format information on hundreds of formats, can be downloaded as XML (ask me for details AndyJackson 15:07, 2 July 2012 (EDT))
 * http://wiki.multimedia.cx/
 * http://archive.org/download/file-format-encyclopedia/fileformat.zip/
 * http://www.digitalpreservation.gov/formats/fdd/descriptions.shtml
 * http://www.udfr.org/
 * http://gitorious.org/re-lab Tools & specs from re-lab- graphics formats, and office formats
 * http://www-mmsp.ece.mcgill.ca/documents/AudioFormats/index.html - Documentation, details, specs, and samples for a handful of audio formats
 * http://wiki.xentax.com/index.php/Game_File_Format_Central This wiki is the home of the most game (archive) file format knowledge in the world.
 * http://rewiki.regengedanken.de has some more game related reverse engineering

Other Useful Materials and Services

 * http://www.nsrl.nist.gov/ National Software Reference Library (see also http://blogs.loc.gov/digitalpreservation/2012/05/life-saving-the-national-software-reference-library/)
 * http://www.openplanetsfoundation.org/software/fido Format Identification for Digital Objects
 * https://github.com/usnationalarchives/File-Analyzer File Analyzer
 * http://sk1project.org/modules.php?name=products&product=uniconvertor UniConvertor is a universal vector graphics translator. It is a command line tool which uses sK1 object model to convert one format to another
 * File Formats for Popular Personal Computer Software: A Programmer's Reference http://www.amazon.com/Formats-Popular-Personal-Computer-Software/dp/0471836710/ref=la_B001KE1CFC_1_1 - @KevinSavetz owns and can digitize this if needed
 * More File Formats for Popular PC Software: A Programmer's Reference http://www.amazon.com/More-File-Formats-Popular-Software/dp/0471850772/ref=la_B001KE1CFC_1_2 - @KevinSavetz owns and can digitize this if needed
 * http://www.textfiles.com/programming/FORMATS/
 * http://wiki.opf-labs.org/display/SPR/Digital+Preservation+Tools Wiki list of digital preservation tool lists
 * http://wiki.opf-labs.org/display/REQ/Digital+Preservation+and+Data+Curation+Requirements+and+Solutions Digital Preservation and Data Curation Requirements and Solutions. Not classified by formats, but by datasets, issues and solutions.
 * http://fileformats.wordpress.com/ - The File Formats Blog