Retrograde

First release. Singleplayer only.

The map — full-screen, opened with O. Real top-down terrain drawn with a colour per block, covering everywhere you've explored rather than just the chunks around you. Four colour modes: terrain, biome, ore density, and where you've been. Slime chunks tinted, Overworld only.

Reading chunks — a fixed panel gives coordinates, visited state, biome and a full scrollable ore tally for whatever is under the cursor. Find filters by scope, visited state, slime chunk, biome and ore, lights the matches up on the map, and selects them nearest-first.

Changing chunks — select up to 256, then regenerate (with a preview first, and undo from snapshot afterwards), run another mod's retrogen (Mekanism so far), re-run the world's ore features, or rewrite the biome in place. The last two are off by default.

Jobs you can get out of — a job moves you clear of the work and puts you back. Cancel is a ladder: stop cleanly, stop now, or let go of a job that has stopped answering. A watchdog on the client tick rescues you if the server thread stops responding.

Known limits: singleplayer only; Find only covers chunks the map has read; regen is all-or-nothing; Mekanism is the only retrogen integration; ore regen has no undo.

It's beta because it hasn't been through many hands yet, and because regen rewrites chunks. Back up a world you care about.