I\'m wondering if it\'s possible to sandbox JavaScript running in the browser to prevent access to features that are normally available to JavaScript code running in an HTML
I think that js.js is worth mentioning here. It's a JavaScript interpreter written in JavaScript.
It's about 200 times slower than native JS, but its nature makes it a perfect sandbox environment. Another drawback is its size – almost 600 kb, which may be acceptable for desktops in some cases, but not for mobile devices.