ClojureScript vs SWC

ClojureScript is a compiler that turns Clojure code into JavaScript for client and embedded application development wherever JavaScript reaches. It brings Clojure data structures and constructs—including functional programming, macros, destructuring, and polymorphism—into JavaScript environments. Its output is compatible with Google Closure Compiler advanced compilation, which can minify output and eliminate dead code. REPL support enables interactive development and testing in a browser or Node.js; the quick start uses browser output by default and selects Node.js output with a target setting. ClojureScript supports both ClojureScript and JavaScript dependencies, with React demonstrated in the quick start. Listed build tools include shadow-cljs, Figwheel, Leiningen, and lein-cljsbuild. Editor resources cover Cursive, Emacs, VS Code, Light Table, Sublime Text, Vim, and Atom. Documentation includes compiler and REPL options, dependencies, advanced compilation, source maps, and JavaScript module support marked Alpha. The project is open source under the Eclipse Public License 1.0 and lists Linux, macOS, Windows, web, and self-hosted environments.

SWC is a free, extensible Rust-based platform for tools that compile and bundle JavaScript and TypeScript. It transforms modern JavaScript and TypeScript into code intended for major browsers, and supports minification, WebAssembly transforms, and custom plugins. Its core API parses ECMAScript, TypeScript, and Flow syntax; the documentation describes that API as mainly useful to build-tool authors. Integrations include webpack, Rspack, and Jest, while Next.js, Parcel, and Deno are among the tools named as users. A WebAssembly module can transform code synchronously inside a browser. SWC can be installed as prebuilt binaries or built from source, with packages documented for npm, Yarn, pnpm, Bun, and Deno. The site states that it is 20x faster than Babel on one thread and 70x faster on four cores. The bundling documentation says that feature will be dropped in v2 and recommends SWC-based bundlers instead. It also warns that its polyfill usage mode is less efficient than Babel for certain dynamically computed property expressions.