WebAssembly High-Level Goals

1. Define a portable, size- and load-time-efficient binary format to serve as a compilation target which can be compiled to execute at native speed by taking advantage of common hardware capabilities available on a wide range of platforms, including mobile and IoT.
2. Specify and implement incrementally:
   • a Minimum Viable Product (MVP) for the standard with roughly the same functionality as asm.js, primarily aimed at C/C++;
   • additional features , initially focused on key features like threads, zero cost exceptions, and SIMD, followed by additional features prioritized by feedback and experience, including support for languages other than C/C++.
3. Design to execute within and integrate well with the existing Web platform:
   • maintain the versionless, feature-tested and backwards-compatible evolution story of the Web;
   • execute in the same semantic universe as JavaScript;
   • allow synchronous calls to and from JavaScript;
   • enforce the same-origin and permissions security policies;
   • access browser functionality through the same Web APIs that are accessible to JavaScript; and
   • define a human-editable text format that is convertible to and from the binary format, supporting View Source functionality.
4. Design to support non-browser embeddings as well.
5. Make a great platform:
   • build a new LLVM backend for WebAssembly and an accompanying clang port (why LLVM first?);
   • promote other compilers and tools targeting WebAssembly; and
   • enable other useful tooling.