ActionScript 3.0
with the Adobe AIR runtime you will be able to publish to iOS, Android, Windows and macOS, see "Adobe AIR" [0]
ActionScript is something similar to TypeScript
you will have access to the whole Flash stack and more, see "Building Adobe AIR Applications" [1]
with ActionScript Native Extension (ANE) you will be able to add your native code with an easy to use AS3 interface, see "Extending Adobe AIR" [2] and "Using native extensions for Adobe AIR" [3]
Note, the latest Adobe AIR SDK are now maintained by Harman [4]
[0] https://www.adobe.com/products/air.html
[1] https://help.adobe.com/en_US/air/build/index.html
[2] https://www.adobe.com/devnet/air/articles/extending-air.html
[3] https://help.adobe.com/en_US/air/build/WS597e5dadb9cc1e0253f...