rs-sb3-0.1.0 has been yanked.
rs-sb3
Rust crate with Serde implementation for json part in .sb3 format. (the Scratch 3 project format)
'extensions' and 'text_to_speech_language' has yet to be implemented (I'm tired) but is planned. Mostly anything else is completely (probably) implemented.
Some documentation are taken from the Scratch Wiki.