It's a library for creating serverside content using custom models and animations, without requiring client mods.
Nylon is a bridge between models created with Animated Java and serverside content (like entities and blocks) written using Polymer, allowing you to combine fancy custom models, textures and animations made in Blockbench with completely custom block / mob logic.

Check out the other pages in the wiki to learn more!

• Setting up Nylon
• Creating and adding a model
• Using the model
• Using locators