WebAssembly High-Level Goals

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.
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++.
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.
Design to support non-browser embeddings as well.
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.