For those unfamiliar, Eagler Craft is a port of Minecraft Beta 1.7.3 (and newer versions like 1.8.8 and 1.12.2 via modded clients) that runs entirely in a web browser using JavaScript and WebGL. No Java. No launcher. No installation. Just a browser tab.
: You can enable cheats during world creation or by opening the game to LAN. This allows you to use commands like /gamemode creative to switch playstyles on the fly. Customization : Eaglercraft supports custom resource packs
When EaglerCraft first launched, the focus was heavily on multiplayer via proxy servers. You needed a server IP to do anything. removes that barrier.
Versions like EaglercraftX 1.8 use an integrated internal server to run singleplayer mode directly in your browser.