FishNet is a comprehensive Unity multiplayer networking framework providing a full client-server architecture with RPCs, sync types, prediction, scene management, observer conditions, and multiple transport backends (LiteNetLib, Synapse, Yak). It employs IL code generation via Mono.Cecil to auto-generate serializers and RPC stubs, achieving high performance and low bandwidth usage. The codebase is well-structured with extensive use of partial classes, pools, and utility patterns. It includes demos for authentication, prediction, collider rollback, and scene management. While the framework is tightly coupled to Unity, many utility components (e.g., object pooling, ring buffers, quaternion compression) are reusable in isolation and demonstrate strong engineering craftsmanship. The project is actively maintained with a large community and regular commits.