Google Web Toolkit vs SWC

Google Web Toolkit (GWT) is a free, open-source Java framework for building AJAX web applications. Its compiler converts Java applications into JavaScript and HTML for browser use, and the SDK includes the core libraries and compiler. Deferred binding generates browser-specific code at compile time, while the compiler can create separate application versions for different browsers and languages. Applications can communicate asynchronously with servers through GWT RPC or JSON. An Eclipse plugin provides IDE support and an option to install the SDK. The developer guide covers deployment to Google App Engine, JUnit unit testing and Emma code coverage; documentation also includes SafeHtml guidance for XSS prevention and GWT RPC XSRF protection. GWT is licensed under Apache 2.0 for non-commercial, commercial and enterprise applications. Version 2.13.1 is listed for Windows, Mac OS X and Linux. Development mode and the compiler periodically send a timestamp ID and product version to Google; Google says it does not log cookies or personal information. The webAppCreator utility has been deprecated since version 2.11.0.

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.