Rust serialization has a long history. At first, there was just some very simple formats. In March 2011, Patrick Walton added support for serializing rust object metadata into EBML (reader and writer. Then in November 2011, Elly Jones added a json library. But their functionality was quite limited, and required manual serialization. So in Feburary 2012, Niko Matsakis created the serialization plugin (1, 2, and 3).
Over time, Erick Tryzelaar took over maintenance of serialization. He converted it over to the new [trait system](https://github.