Mojang (now Microsoft) has a strict policy: You may not distribute modified versions of the Minecraft client or server software.
Because Eaglercraft 188 Repack redistributes game assets, it technically violates the Minecraft EULA. That said, Microsoft has historically ignored non-commercial, browser-based ports. They tend to issue DMCA takedowns only when the repacks include a cracked launcher or enable multiplayer without a legitimate Minecraft account.
Enter the . What Exactly is the "Eaglercraft 188 Repack"? The term "repack" in this context refers to a pre-configured, ready-to-launch bundle of the Eaglercraft 1.8.8 client. Unlike the original source code (which might require compiling or command-line tools), the Eaglercraft 188 Repack is designed for instant gratification.