This is a collection of tools, libraries, and mods I’ve written for the Java edition of Minecraft over the years.
Tools
NBTExplorer
One of the best-known tools for viewing and editing Minecraft data at its lowest level, which is stored as NBT data. It can edit standalone NBT files like player data, as well as region files that store world data. NBTExplorer is written in C# and runs on Windows, Mac, and Linux (with appropriate .NET or Mono runtimes installed).
NBTUtil
A small commandline utility that comes with the NBTExplorer download. It has limited ability to read and modify NBT but can still access all of the same data files that the explorer can. This tool is more suitable to GUI-less server environments and may be more amenable to automation.
NBToolkit
An older collection of commandline utilities for working with Minecraft worlds, featuring operations like world trimming and ore generation. It hasn’t been maintained in several years, so your mileage may vary.
Libraries
Substrate
A full .NET SDK for working with Minecraft data. It supports different abstractions, from raw NBT to levels and worlds and users. The lower levels are still pretty solid, but frequent changes in Minecraft’s own data representations have rendered the higher-level abstractions mostly useless.
NNBT
A standalone .NET NBT library. Beyond basic reading and writing, it supports some extra features like NBT merging. It only supports standard NBT files.
Forge Mods
Storage Drawers
By far my most popular mod. It does what it says on the tin – it adds storage drawer blocks to the game. These blocks are based on the interaction model of previous “barrel” mods like JABBA, where items are added and removed by clicking and punching the face of the block. More powerful blocks allow auto-compressing items or controlling networks of drawers from a single point.
Garden Stuff
A decorative mod adding items that might be befitting of a garden. Or an industrial complex.
Hunger Strike
A small mod that effectively disables the hunger system, bringing the health and healing mechanics more in line with Minecraft’s alpha and early beta releases. Can be enabled on a per-player basis in server settings.
Extra Buttons
A small mod that adds a few colored toggle buttons and a few other button-related blocks.
Big Doors
An addon mod for Malisis Doors; it adds several styles of 3×3 block-sized double doors. As of late versions of Minecraft 1.12, this mod has been merged directly into Malisis Doors, so is no longer maintained as a separate mod.
Bukkit Plugins
OrePlus
A plugin that can generate various block/ore configurations on Bukkit servers. Although this plugin has not been updated since 2013, it’s still working as intended at least through Minecraft 1.12.