WebAssembly (Wasm) represents an important stepping stone for the web platform. Enabling a developer to run compiled code on the web without a plugin or browser lock-in presents many new opportunities. Some confusion exists about what WebAssembly is, as does some skepticism about its staying power.

In this chapter, we will discuss how WebAssembly came to be, what WebAssembly is with regard to the official definition, and the technologies it encompasses. The potential use cases, supported languages, and limitations will be covered, as well as where to find additional information.

Our goal for this chapter is to understand the following:

• The technologies that led the way for WebAssembly
• What WebAssembly is and some of its potential use cases
• Which programming languages can be used with WebAssembly
• The current limitations of WebAssembly
• How WebAssembly relates to Emscripten and asm.js