Eaglercraft does distribute Minecraft assets (like sounds or default textures). It uses a clean-room reimplementation of the protocol and graphics. That said, Mojang’s EULA frowns on recreating the game exactly. The project stays in a legal gray area, but it has existed for years without major takedowns.
Is it a cheat code? A version number? The secret to running Minecraft at 120 FPS for free in a browser? eaglercraft 120 1 free