Most of you probably already use this, but if you don't, this can be a heavy time saver.
I just started messing with the gui last night and discovered this, but couldn't get to website so this is my first chance to post.
This only works if you have two computers networked together, which most of you probably have.
For this example, Computer 1 will be the computer you play EQ on and Computer 2 will be the production computer. "Mine" will be the name of the mod that we use.
Ok, first, share your Everquest folder on Computer 1 over the network (you could just share the mod directory, but then you wouldn't have access to uierrors.txt)
Now, log in to the game with Computer 1.
On computer 2, pull up the Everquest directory from Computer 1 (using the network of course) and the developing tools you use to create your mods.
Here is the cool part, Everquest allows you to modify the files while in game, so you can edit the .XML files on Computer 1 (thru using Computer 2) without crashing the game (I think you see where I'm going with this).
So, make a hotkey on your character logged in on Computer 1 that's titled "Mine" and have it type "/loadskin Mine 1".
Now, all you have to do is edit the XML in Computer 1's Mine folder using your second computer, hit save, and press the "Mine" hotkey on your first computer.
Violla, You can now see the changes you made to your window imediately, while still in production.
For those of you who constantly log on and off to check changes, this will save you a lifetime, and the mods that you develope will be near bugless since you can check the changes while still writing the code.
P.S. Since you're sharing the whole EQ directory, if there is some problem loading your skin and it loads the default back, you can get access to the uierrors.txt file as soon as it's writen and fix the problem without logging out.
Hope this helps everyone.