What Chunky does
Chunky is a server-side plugin that pre-generates world chunks before players reach them. You pick an area, start a task, and it works through that area chunk by chunk. Folks who try this can run a single task, or start several in parallel to put more of your CPU to work. Any running task can be paused, and its progress is stored so you can resume it later. As it runs, it shows how many chunks are done, how far along it's as a percentage, an estimated time to finish, and how fast it is currently processing chunks.
Selecting an area
You set a world, a center point, and a radius, or you define the area by its corner coordinates. The shape of the selection can be changed. Here's the thing, separate commands snap the selection to the world border of the chosen world, or to its spawn point. A trim command removes chunks that sit outside the current selection. You can also choose the pattern that controls the order generation runs in, and silence or space out the progress messages.
Who it's for
Server admins who want terrain built on their own schedule rather than when a player first loads that part of the map. It suits servers with a bounded map, or ones that want the area around spawn fully generated before opening to players. The pause and resume behavior helps with big jobs that won't finish in one sitting.
Compatibility
Chunky runs on the server. The Hangar listing marks client side as unsupported and server side as required, and names Paper as the supported platform. A project's repository says it works with many server platforms and names Spigot, Paper, Fabric, Forge, NeoForge, and Sponge. One license is GPL.
Supported Minecraft versions are listed one by one on Hangar: 1.18, 1.18.1, 1.18.2, 1.19, 1.19.1, 1.19.2, 1.19.3, 1.19.4, 1.20, 1.20.1, 1.20.2, 1.20.3, 1.20.4, 1.20.5, 1.20.6, 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11, 26.1, 26.1.1, and 26.1.2.
World border support is optional and depends on the separate ChunkyBorder addon. Without that addon you can still use custom world shapes and radius based selections.
Extras
The project page links a wiki for feature documentation, a Discord server with a dedicated #chunky channel for questions, a Crowdin project for translating the plugin, and a bStats page. It also shows an example of three worlds generated at the same time on a Ryzen 3700X with 16 GB of RAM.
