The complete C/C++ to WebAssembly compiler toolchain with POSIX emulation, OpenGL-to-WebGL translation, and pthreads support.
Emscripten is the most capable toolchain for compiling existing C and C++ codebases to WebAssembly. It provides a POSIX compatibility layer that emulates the filesystem (MEMFS, IDBFS), pthreads via SharedArrayBuffer, SDL2, OpenGL via WebGL translation, and dozens of precompiled ports of popular libraries (zlib, libpng, libjpeg, freetype, harfbuzz). Projects like SQLite Wasm, ffmpeg.wasm, Google Earth, and Figma were all built with or ported using Emscripten. It remains the standard toolchain for any project with a large existing C/C++ codebase.
The standard library for high-level Rust ↔ JavaScript interop in WebAssembly projects.
The one-stop build tool for compiling Rust to WebAssembly and publishing the result as an npm package.
A TypeScript-like language that compiles directly to WebAssembly — no Rust or C++ required.