Most people know of multi-world mods. An example is Multiverse. Also, many people know of Inception, a mod that links worlds in layers. The default minecraft system generates terrain infinitely. Therefore, the land expands out infinitely left and right, front and back. However, the 128 height limit is rather restricting for people like me who like to over size things (not saying I'm a great builder, I just like sizing things up). What I am requesting is a level generator plugin that generates "underground" maps, maps where layer 0 to 128 are entirely generated the same way that the underground areas in the base generator is, except that ores are spread everywhere (because in an inception connection it would be all underneath even the diamond. If done this way, theoretically, we could make maps that are infinitely tall and deep, as there is already a "space" world generator that is able to make empty sky maps. This may seem a little bit less important now, as the 1.8 update will supposedly expand the height limit to 512, however, evern with a height of 512 a generator for underground maps would still be useful for expanding past even that.
