Elements in the world are actually Java objects, so you can create your own world elements relatively easily. This system is very flexible, and you can create very different types of worlds.
Messages appear in the heads-up display.
Other users appear as spheres with faces, and have their machine name above their head. The mouse controls how you move in the world. Click the mouse buttons and move the mouse to navigate. Use the left mouse button to rotate left and right. The middle mouse button moves you forward and back.