JTRANSC
Bytecode to source converting Java & Kotlin code into JavaScript, C++
JTransc (Java Trans Compiler) is an AOT (ahead-of-time compiler) that compiles .class and .jar files into a target programming language / executable bundling all the required dependencies in a single file or folder, without requiring a jitter or an external runtime. There are a lot of technologies in order to convert languages into other ones. For example, converting Java into JavaScript. Or KotlinJS Kotlin backend that already targets JavaScript.