BepInEx vs Everest

BepInEx is a plugin and modding framework for Unity Mono and IL2CPP games, as well as .NET Framework games such as those built with XNA, FNA, and MonoGame. It provides configuration and logging, runtime method patching, and in-memory assembly patching. Runtime patching uses Harmony, including HarmonyX and MonoMod; in-memory patching uses Mono.Cecil with UnityDoorstop. The installation guide lists Windows, Linux, and macOS, though supported operating system versions and architectures depend on the build and game. Setup is manual: download the appropriate build and put its contents in the game’s root folder. Official binaries are available as stable and bleeding edge builds; the documentation recommends stable in most cases and notes that bleeding edge builds tend to be buggier. The project is open source under LGPL-2.1 and links to guides for users and developers. Compatibility has limits: stable releases are available only for Unity Mono, BepInEx 6 documentation remains a work in progress, and BepInEx 5 plugins do not yet work with the 6.0.0 pre-release.

Everest is a free, open-source mod loader and modding API for Celeste. It lets players use mods with custom maps, texture replacements and code-driven additions such as sound effects, graphics, dialogue and campaigns, without changing original game files. An in-game updater and dependency downloader help manage mods. The cross-platform Olympus installer can install mods with one click from its Download Mods section or GameBanana, or from ZIP files and folders; players can also switch between Everest and vanilla Celeste through Olympus or the title screen. Everest supports Windows, macOS and Linux and works with Celeste from itch.io, Steam and Epic Games, but not the Windows Store version. Enhanced Debug Mode offers live map reloading, code and asset reload shortcuts, an improved map viewer and console logging. The project is MIT-licensed and maintained by volunteers. Olympus is actively being worked on and may fail, and the project directs users to the Celeste Discord’s #modding_help channel for bug reports and questions.