It is still a young modification and hasn't yet spread widely, but there are some scripts already made, and it aims to become the complete modern CLEO replacement! MoonLoader provides to developers extensive functionality for modding, it includes all familiar capabilities that CLEO has, and also combines many new features that were not previously available together in any GTA: SA modding framework. With Lua scripts you can change some game aspects, expand gameplay and add new features.
MoonLoader is a modification for GTA: San Andreas that brings new ability to use Lua scripts made by mods creators.