Servo is Mozilla’s next-generation web browser [1], with a focus on parallelism and security. It’s not much more than a technology demo and will remain so for a while, but it’s making progress nonetheless. Quoting Patrick Walton in a thread on Google Groups:

In this blog post, we give a name to JavaScript’s callback-based asynchronous programming style: continuation-passing style (CPS). We explain how CPS works and give tips for using it.

In general, arrays in JavaScript are sparse – they can have holes in them, because an array is simply a map from indices to values. This blog post explains how to create dense arrays, arrays without holes.

[2015-02-26] New version of this blog post: “Iterables and iterators in ECMAScript 6”

ECMAScript.next’s for-of loop will provide a new and quirk-free way of iterating over all kinds of data. This blog post explains how it works and how you can try out a prototype implementation in Firefox 13 and later.

Underscore.js is a highly useful complement to JavaScript’s rather sparse standard library. In a pinch, Underscore gives you simple templating, too. This post explains how it works and gives tips.

Technical publisher O’Reilly organized their first JavaScript conference, called “Fluent”, May 29-31 in San Francisco. This blog post collects random impressions of mine from that conference. They should be interesting even if you haven’t attended Fluent (hint: links to videos).

Modules are mostly the same in Node.js and AMD [1]: A sequence of statements that assign internal values to variables and exported values to an object. This blog post shows several patterns for doing the latter. It also explains how ECMAScript.next handles exports.

All numbers in JavaScript are floating point. This blog post explains how those floating point numbers are represented internally in 64 bit binary. Special consideration will be given to integers, so that, after reading this post, you will understand what happens in the following interaction:

    > 9007199254740992 + 1
    9007199254740992

    > 9007199254740992 + 2
    9007199254740994

This blog post explains how one can use Node.js to expand a URL that has been shortened by a service such as t.co (built into Twitter) and bit.ly. We’ll look at a simple implementation and at an advanced implementation that uses promises.

The new attribute download for <a> tags allows one to offer a file for download – instead of displaying it in the browser.