When a Spigot server starts with oraxen installed, the plugin will read all the item configurations and use them to generate json models to link your png textures to your items. It will zip the resources using an optimized algorithm and upload it to a polymath instance. Polymath is a free and opensource software written in Python to host minecraft resourcepacks. By default oraxen will use my own instance, hosted in Switzerland on an oracle virtual private server. When a player will connect to your server, oraxen will link him to the polymath instance which will server him the resourcepack.