Hey guys,
I've been working on a library and so far it offers support for two specific types of Itemtype.dat file structures.
One being EO Version 4 (approximately around version 1106)
The other being based on what Korvacs posted in

.
However there is support for loading ALL itemtypes that keep to same principles that TQ use. I've tested on multiple EO/ZO/CT and a fake (I made it myself) of Korvacs structure deffinition.
It will only load the ID/Name/Description fields, but it will still load the rest of the data into unknown block(s) which you can extract/read from.
I will be using this library to make an app that should allow for a GUI based itemtype editor that will support any itemtype file.
Documentation will come as it's dramatically been changed since I uploaded in EO section.
Same concepts though, use the "FileReader" class to read in Itemtype files and use the FileWriter class to write them.
Here is a link to the old documentation if you still want it to get the basic idea:
Documentation (unfinished):