Transpiler
A transpiler (source-to-source compiler) is a tool that converts source code from one programming language to another at the same abstraction level, often to enable compatibility with different environments or to use modern language features in older systems. It transforms code while preserving the original logic and structure, making it executable in a target runtime that doesn't natively support the source language. Common examples include converting TypeScript to JavaScript or modern JavaScript (ES6+) to older versions for broader browser support.
Developers should use transpilers when they need to write code in a language with advanced features (e.g., TypeScript for static typing) but must run it in an environment that only supports a different language (e.g., JavaScript in browsers). They are essential for cross-platform development, polyfilling new language features, and improving code maintainability through type safety or syntactic sugar, without sacrificing compatibility with legacy systems or diverse runtimes.