From now on, some of the game data files will be put inside of one big file and thus made available for developers (that is, me) only. I strongly believe that it is essential for a roguelike game to keep some of game's internals in secret. Now I will be able, for instance, to create quests that would become a lot easier of one could take a look at the script files.
That change has at least one undesired side effect. The game is not customizable anymore, not to the level it used to be. However, I don't think it's that important for a roguelike. All in all, most of the few really successful games of that genre were not customizable and none of them were mods (as far as I know). Apart from that, I will provide a new mechanism of customization in the future.
Of course, the protection mechanisms for the Big File are quite easy to break if you know some assembly... I hope that nobody will actually attempt to reveal Untitled's secrets.