This mod makes certain blocks overtake others slowly over time. The blocks that spread are those in #blockspreading:spreads, and the blocks that can be overtaken are in #blockspreading:substrates. By default the only block that spreads is netherrack, and it can spread into ordinary overworld stones.
In multiplayer, this mod only needs to be installed on the server, as it adds no blocks or items.
The Block Spreading Team
Owner
