We are aiming to produce a product for general use by the time of the DH conference presentation, and to add info about it to an edited version of the conf paper due at the end of the month, so pushing forward with more straightforward stuff this morning. Added file-existence checking for XML and text files; experimented with methods of checking for the existence of binary files, but so far I've only found things that work in Saxon PE or EE. This approach might work, though.