... musings on the topic of proprietary data formats, when to use them and how to mitigate their downsides.

Case in point: Arcitecta's AAR format

  • Seems to be a good idea ... an archive format that is designed to allow parallel compression.
  • No published format specification of any form.
  • No published reference implementation:
    • Arcitecta's CEO has informally given permission to redistribute the "aar.jar" file, but the situation is not legally clear.  Certainly, he / they have not made any public statements on this.
    • They don't make it directly available for download.  You have to ask for it, or find it elsewhere.
    • It is an (obfuscated) binary ... which is not adequate as a reference implementation for the purposes of someone trying to understand the format and/or create their own implementation.
  • Minimal information for someone trying to identify an AAR file:
    • The ".aar" file extension is not known in any of the online "file type" sources
    • Almost no useful Google hits.
  • Arcitecta have said (privately) that they are going provide a specification document and a reference implementation.  But they haven't done so ... yet.
  • Meanwhile Arcitecta are encouraging customers to use "aar".