WorldAndGenerationTweaks by Thebombzen
WorldAndGenerationTweaks provides various assorted tweaks to terrain generation.
WorldEdit by sk89q, wizjany, TomyLobo
WorldEdit is an easy-to-use in-game world editor for Minecraft, supporting both single player and multiplayer.
WorldEdit CUI Forge by lahwran, yetanotherx, nejinx
WorldEdit CUI Forge is the ModLoader ported version of the client-side only mod that adds an in-game visual overlay for WorldEdit selections. There is no support for SinglePlayerCommands.
WorldEdit CUI Forge Edition by yetanotherx, Mumfrey, Hexosse
WorldEdit CUI is a client-side user interface for WorldEdit.