Hi,
if you are familiar with programming, I recommend having a look at this
file:
http://code.google.com/p/fluorescence/source/browse/src/fluorescence/data/manager.cpp#127
This is where all the data loaders are initialized.
Basically, you need a full Ultima Online installation to run
fluorescence, although not all files are in use yet.
I plan to write some more docs on how to customize fluorescence (e.g.
overwrite mul textures) in the foreseeable future. But can't really tell
when I have the time and motivation for documentation ;)