Whack™ will allow you to build apps and games through the ActionScript 3 language targetting HTML5. The SDK's compiler is being implemented in Rust, where I have finished the preliminary of what is known as a "type checker".
Verifier
The verifier, also called "type checker", ensures the program is correct ahead of time and maps nodes to entities in the semantic model.
ActionScript: 100% (excluding the following meta-data: [Bindable], [Embed] and [StyleSheet] and others related to Whack)
MXML and CSS are languages that have a 1-1 mapping to ActionScript. They can only be done once the framework APIs are finished, and they are not a priority.
MXML: 0%
CSS: 0%
Built-ins
Language globals: 100%
"Whack" framework: 0%
ActionCore
ActionCore is a "semi" virtual machine for ActionScript 3 implemented in JavaScript for use by Whack's compiler.
What is next
Package manager
The package manager is what I am looking into working in right now, which aims to be as flexible as the Cargo package manager.
I really want to see this happening.