Sucrase is described as 'alternative to Babel that allows super-fast development builds. Instead of compiling a large range of JS features to be able to work in Internet Explorer, Sucrase assumes that you're developing with a recent browser or recent Node' and is an app in the Development category. There are more than 10 alternatives to Sucrase for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Node.JS. The best alternative is Typescript, which is both free and Open Source. Other great apps like Sucrase are Dart (Free, Open Source), Kotlin (Free, Open Source), CoffeeScript (Free, Open Source) and Haxe (Free, Open Source).
Haxe is an open source toolkit based on a modern high level strictly typed programming language, a state-of-the-art light-speed cross-compiler, a complete cross-platform standard library, and ways to access to each platform's native capabilities.
Hack is a programming language for HHVM that interoperates seamlessly with PHP. Hack reconciles the fast development cycle of PHP with the discipline provided by static typing, while adding many features commonly found in other modern programming languages.