Prevent Crappy Launcher

The mod is a LaunchWrapper and ModLauncher CoreMod. Its purpose is to stop players from launching Minecraft through a launcher it classes as crappy. The author notes that such launchers can cause performance and compatibility problems that are very hard to diagnose, including when the game files are altered quietly or extra JVM parameters are added for optimization reasons.

The author also describes such launchers as a possible computer virus hazard, citing system-level libraries such as kernel32 and suspicious activity. The planned approach is to detect crappy launchers that are exclusive to an operating system, using several methods, and to throw exceptions to players who try to launch the game with them. Modpack authors are expected to handle some of the confusion this causes. Files are published for Forge and NeoForge across 77 release versions, 1.6.4 – 1.21.6, under the Mozilla Public License 2.0, and the mod is open source. Servers do not need it; each player installs it for their own game.