BepInEx vs Ultimate ASI Loader

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.

Ultimate ASI Loader is a free Windows proxy DLL that loads custom .asi libraries into a game process. It supports games using Win32 or Win64 libraries such as Direct3D, DirectInput, audio, and XInput. Installation usually means placing the DLL in the game directory as dinput8.dll, or renaming it to another supported DLL name. ASI files can be stored in the game root, scripts, plugins, or update folder. When needed, global.ini belongs in scripts or plugins, and the selected DLL name can also serve as the INI filename. The update folder can hold replacement game files while originals remain untouched; removing that folder reverses the change. The loader can forward many original DLLs after renaming them Hooked.dll, and d3d8to9 support is available when it is named d3d8.dll. Crash minidumps and logs are created when a CrashDumps folder exists beside the loader. Win32 and Win64 builds are available, including smaller NoPDB archives. The repository lists an MIT license.