mdxlib-3.0.0.12.jar is a release file of the Minecraft resource pack Simply Seasons Seasonal Music, made for Minecraft 1.12.2. It was published on March 13, 2019 and is 0.4 MB in size. For the full description, screenshots and every other version, visit the Simply Seasons Seasonal Music resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.
