How? User can download something in tar.bz as a pure dictionary file, zip folder with set of files or even the full English wikipedia with cache. How can program know all this? I know an application for iPhone that comes with simple dictionaries and is able to download a lot of dictionaries on demand, but that's paid service and those dictionaries cost money and it's not even possible to upload them anywhere without being sued by Babylon or Abbyy. I don't see a problem to download a dictionary and then unpack it to some specific directory, there is even an option to define several directories to these dictionaries. One solution that I can suggest is to unpack all zip/tar.gz files found in the defined dirs into the same directory with removal of the archive files.