Rust extends far beyond its system programming domain and can be made to run on the web as well. In this chapter, we'll explore one such technology for doing this, called WebAssembly. We'll go into the details of what exactly WebAssembly is, and how Rust can be made to run alongside JavaScript using this technology.Being able to run on web browsers unlocks a domain that enables Rust to be used by a much larger audience, that is, the community of web developers, and enables them to leverage the performance of a systems language in their applications. Later in this chapter, we'll explore the tools and libraries that offer WebAssembly support, and build a live markdown editor that invokes an API implemented in Rust for rendering markdown documents to an HTML page.

In this chapter, we will cover the following topics

• What is WebAssembly?
• The goals of WebAssembly
• How can WebAssembly be used?
• The tale of Rust and WebAssembly and available crates
• Building a WebAssembly-based web application in Rust