A C# serializer a la Cap’n Proto. Data is not really serialized and deserialized but a data wrapper is generated to dig into byte when possible. Deserialization is really quick but an time penalty occures on each access. Really efficient when only a small part of deserialized data are needed. You pay only for what you use.
No DSL (like .proto) is used but serialized type must permit subclassing properties acces. Each property must be virtual and a derived class is dynamically generated under the hood. A pre compiler exists for Unity.