VoxelDesc is a voxel editor driven by a command line, for Java 6 and later, with 2.5D graphics and powerful scripting.
Typical voxel editors would have you place every single voxel by clicking with the mouse, which is slow, repetitive and error-prone. All the tedium of Minecraft with none of the fun! By contrast, VoxelDesc will allow you to say things like
scene.color(red).from(-2, -2, -2).fill(4, 4, 4). This is not for everyone. But in the right hands, it should enable the creation of sophisticated scenes.
As of 2014-10-25, VoxelDesc is starting to look like a complete app. Bugs and limitations undoubtedly remain.