Javascript is the universal programming language of the web. Almost all web sites use it to some extent, including this site (boot13). Although many users (including myself) use Noscript and similar systems to block Javascript when browsing unfamiliar sites, it’s difficult to use many popular sites without it. For example, I spend a lot of time using Google Analytics, and I’ve configured Noscript to allow JavaScript code to run on that site.
One of the problems with JavaScript is that it’s a scripted language. That means your web browser has to parse JavaScript code, one line at a time. This is a very slow process, and contributes to slow loading times on many major sites.
Various efforts to speed up JavaScript have come and gone, without much traction. Now, several major software developers have teamed up to try again. A new JavaScript assembler called WebAssembly (aka wasm) is under development by Mozilla, Microsoft, Google, and Apple. It’s too soon to know exactly when WebAssembly will start appearing in web browsers, but we’re hopeful that it will become the new standard when it does.