EDIT: GNARR! New Anvil file format invalidates this tool entirely. I could fix it, but I'm not planning on it. This repo contains Racket code for reading/writing minecraft .mcr files. It includes a command-line interface, minecraft-cli.rkt. To build an executable, run raco exe -o mcr-tool minecraft-cli.rkt ... and then run mcr-tool --help for help on the options.