to set up a 1.8.8 server, then install the EaglercraftXBungee plugin to make it accessible to web players. For Developers : Download the EaglercraftX-1.8-workspace from GitHub to manually add code-based modifications. , or do you need help setting up a modded server
Beyond scripting, players use standard Minecraft assets that have been adapted for the browser: mods for eaglercraft