Produced by: Nodling Dragon, Glanestel Dragon
Website: Ultima Tech Info and Patches
Much as with Nodling’s equivalent utilities for Ultima 4, these programs allow you decode (decompress) the LZW-compressed data files that Ultima 6 uses, and then re-encode the expanded files (which you could, say, have modified somehow) in a way that Ultima 6 can read (although not with the LZW algorithm, which was patented at the time these utilities were written). Nodling Dragon points out that when one uses the encoder, the resultant file will be a bit larger than the equivalent “original” file, for this reason.
Glanestel Dragon has since produced an updated version of u6decode which will work on Ultima 6’s conversation files as well. The files are, apparently, not entirely encoded with LZW, but do have LZW-compressed data blocks within them. Nodling Dragon’s original version can’t handle these files.
Also available here is Nodling Dragon’s incomplete technical reference document for Ultima 6’s game data.