This Model Editor is not made by me, but is made by Magos.
War3 Model Editor is as the name suggests a Model Viewer and a Model Editor dedicated to Warcraft 3. It supports both loading and saving of .mdl and .mdx model formats which are used in Warcraft 3. It also supports .bmp, .tga, .png, .jpg, .jpeg, .pcx and .blp texture formats.
There is a buildt-in MPQ Browser that allows you to browse any MPQ archive, which also includes Warcraft 3 map files (.w3m and .w3x). The MPQ Browser has been optimized for speed and is very fast to load and use. The Browser is customizable so you can add/remove your own icons and filters.