Furthering the JavaScript Runtime

Looking ahead, there is a great opportunity for JavaScript to continue to evolve the core runtime. From talking to developers building HTML5 Web sites, we understand that these areas represent the most value:

• Better integration with the native browser platform. With the introduction of recent APIs in HTML5, such as the File API, Canvas Pixel Array, and XHR2, there is an increasing need for JavaScript to have better interoperability with binary data streams. The need is so acute that there are many proposals across many Web communities and they are starting to converge in the Binary Data proposal. The Binary Data proposal aims to improve usability and expressivity for the use cases above.
• Improved site load, especially for larger sites. JavaScript today would benefit from a standardized pattern for loading units of code consistently, in a way that won’t cross-contaminate the global scope, with a predictable loading order. A solution would benefit from being integrated into the runtime to ensure efficient page load times in coordination with the other browser subsystems. The modules and module loader proposals look like promising starting points which we aim to make available to scripts in “text/javascript” without needing to introduce breaking changes.
• Execution performance and responsiveness. Libraries for interacting with intrinsic JavaScript types should continue to be filled out. As the String and Math extensions proposals suggest, JavaScript would benefit from an intrinsic string search like startsWith or contains and additions to the set of math functions to match other client platforms. JavaScript would also benefit from a format capability to replace variables in strings. Like ES5, when integrated into the runtime, these features can provide clear performance improvements for many real-world Web sites with minimal developer effort.