I’ve built a another simple scrolling tile map editor, the source is included as well as a few samples and html docs. Both MacOS X and Windows executables are included in the zip. Eventually I’ll have a Linux version as well.
This is in the Off Topic section because it isn’t written in Java but the file format is documented and I thought it might be usefull to someone here.
You can find more info here: http://www.scottshaver2000.com/forum/viewforum.php?f=17
The survivor map editor is probably going to be released in the near future as an extensible general-purpose game-map editor.
I say this because we needed a BIG map editor at work recently, and the survivor one was easy to hand 
so I’ve been going through fixing bugs and modularising it so it can handle the proprietary map formats we’re using.
Just an FYI.
Version: 0.4.0 (Alpha)
Release Date: 8/4/2005
Changes:
Updated the documentation.
Fixed a bug in the tile selector window that caused only some tiles to be displayed.
Removed the recent files menu item, until I get around to making it work.
Removed the layer properties menu item, until I need it.
Added support for the mouse scroll wheel to select the current draw tile.
Added the ability to shift the cells in the current layer with the arrow keys when the shift key is pressed
Added the ability to shift the cells in all layers with the arrow keys when the control key is pressed
Windows and Mac executables are included.
I may have the wrong Mac exe in the archive could someone please run it on a Mac and verify that the Help|About dialog says 0.4.0?