Alternatives to MelonLoader
Universal open-source mod loader for Unity games built on IL2CPP or Mono. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
MelonLoader
Universal open-source mod loader for Unity games built on IL2CPP or Mono.
Replacements
Listings that take over the same core job as MelonLoader.
BepInEx
Open-source plugin and patching framework for modding Unity and XNA games.
BepInEx is an open source plugin and patching framework that covers Unity and XNA games and runs on Windows and Linux, with per-game setup required.
Similar software
Related functionality, not a direct replacement.
Vortex
Official Nexus Mods manager that installs, sorts, and updates mods for hundreds of games.
Mod Organizer 2
Power-user mod manager using a virtual file system, favored for Bethesda games.