Neolithic.jar is a release file of the Minecraft mod Berserker's Additions: Neolithic for Forge, made for Minecraft 1.17.1. It was published on January 25, 2022 and is 0.2 MB in size. For the full description, screenshots and every other version, visit the Berserker's Additions: Neolithic mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.