HybridCLR is a runtime extension for Unity that transforms the IL2CPP engine from a pure ahead-of-time compiler into a hybrid AOT and interpreter runtime, enabling native C# code hot updates across all IL2CPP-supported platforms including iOS, consoles, and WebGL.
The tool solves the problem of deploying code updates to shipped games without requiring a full reinstall. It extends IL2CPP's runtime capabilities to dynamically load assemblies, which the standard AOT-only runtime cannot do. By implementing an efficient register-based interpreter alongside AOT compilation, the project achieves hot updates while maintaining performance comparable to native AOT code. The approach includes differential hybrid execution, which intelligently runs unchanged functions as AOT code and only interprets modified or new functions, minimizing performance overhead.
Developers should choose this tool if they need C# hot updates across multiple platforms, particularly iOS where alternatives are limited. It suits projects already using Unity's standard workflow, as it requires minimal integration effort and no special coding patterns. Unlike other hot-update solutions, it supports multithreading features like volatile and async Task, works seamlessly with MonoBehaviour and ScriptableObject, and handles generics and reflection without code generation. The project also supports hot reload for complete assembly unloading and hot fixes that resolve bugs without game restarts.
The project maintains comprehensive documentation including quickstart guides and performance benchmarks. Development activity shows sustained attention to feature completeness, with support for ECMA-335 specification compliance and only a small set of unsupported features explicitly documented. The team has built complementary tooling including code obfuscation and native scripting integrations for Lua and TypeScript. The codebase demonstrates focus on production readiness, with documented memory efficiency reports and support for modern DLL encryption to protect code security.
