Non-EMU related: Mapfiend's maps.
 

I downloaded a zip of map files from Mapfield from some forum a few days ago (it might have even been here).

Inside the zip are text files full of coordinates. I imagine they're used to draw up the maps using lines etc. Anyone happen to know what program I need to use to make images out of these?

It sounds like you may have the .map zone files that work with the EqAdmin Tool.

Yes those are the maps used by eqadmin (and ShowEQ). They are not used by EQEmu itself, just EQadmin. There was a program that would display them as images, but it was broken by some of the larger maps and never updated. The mapfiend web site has the ability to produce the images from the files though.