Dungeon Master Java is a DM clone created by Alan Berfield.
In addition to the excellent graphics and gameplay, here's some more modifications that might interest the DMJ enthusiast.
These modifications include new graphics and extras to the Java code.
Firstly you will need the Java runtime JRE1.4. If you check out the link to Germany's site, you will see he has an extensive list of DMJ goodies for you to download. The Java runtime and information regarding installation you will find here,alternatively you can go straight to the website here:- http://java.sun.com/j2se/1.4/
You may also wish to check out the other links. Alan Berfield's official DMJ site still offers information regarding installation and documentation on using the editor. Alternatively, you can download Germanny's PDF version, which explains in detail on how to use the DMJ editor.
The Dungeon-Master forums, is also a great place to visit, and offers a friendly home to all DM style gaming enthusiasts.
It offers friendly advice into other DM clones like RTC (Return to Chaos) - which is also accompanied with an editor to create your own dungeons and graphics. You can find more information over on the forum as well as just a friendly chat.
Take a look at some of the piccies. These are just a few of the modifications completed so far.
To get the latest addon pack v0.1 head over to the download section.
Keep checking back for newer updates, addon pack v0.2 will be available there soon.
Fireplace graphics. Coded as both wall decoration and wall switch, allowing the user to use a "key" to reveal a secret passageway (a bucket of water, for example).
Available in addon pack v0.2.
Germanny has also given the DM community a resourse site.
Check out the link to Germanny's site for more textures.
Here's one of his boulder's - just a little resizing and it looks good in DMJ.
Available in addon pack v0.2.
Combined with Germanny's graphics of his walls and tree deco - and a little inspiration from Crimson Ghost, we have a new wallset. Check out the piccies for the "weather scenes" created for them, both snowy and rainy versions.
Available in addon pack v0.2.
Town Interiors
Complete with events to interact with the townsfolk.
Here you can buy rare weapons and/or armour.
Available in addon pack v0.2.
Create a free website at Webs.com
Winter Wonderland. (Snow Animates). 
New fountain to go with the snowy town theme. 
Rainy Days.
A new teleportation device. This does not replace the existing graphics default to DMJ.