- New function type syntax
- Arrow function syntax
- final keyword
- New and faster Haxe built-in interpreter
- Unicode support on all targets
- Key-value iterators
- Auto-“using” for types
- IDE services protocol for better IDE support
- New high-performance run-time HashLink, a successor of Neko
- .. and much more!
Check the complete What’s New Guide for a full list of changes in this release, including possible breaking changes from Haxe 3.x. There is a thriving ecosystem of game engines and frameworks for Haxe which we showcased here. Of particular interest are the Blender based Armory3D engine (tutorial series here) and the popular and mature 2D frame HaxeFlixel (tutorial series here).
You can learn more about the Haxe 4.0.0 release in the video below.