In the midst of the WikiLeaks Vault 7, Mozilla quietly released Firefox 52, which has officially become the first web browser to support the new WebAssembly standard.

Work on WebAssembly started in 2015, and from the get-go, the standard had support from all major browser vendors.

WebAssembly will revolutionize the Web

In layman’s terms, WebAssembly is a binary format for web pages. Its main advantage is that it allows developers to pack web page resources in a smaller payload. WebAssembly reduces page load times but also brings a near-native performance by delivering “ahead of time” compiled code.

Instead of receiving JavaScript code that Firefox needs to interpret, WebAssembly allows developers to pre-compile their code into low-level, machine-ready instructions that Firefox can run right away after finishing the download.

With WebAssembly, web pages become both faster, but also more powerful, allowing developers to deliver more complex and optimized code to web users.

“This new standard will enable amazing video games and high-performance web apps for things like computer-aided design, video and image editing, and scientific visualization,” says David Bryant, Head of Platform Engineering at Mozilla.

“We expect that WebAssembly will enable applications that have historically been too complex to run fast in browsers – like immersive 3D video games, computer-aided design, video and image editing, and scientific visualization. We also expect that developers will use WebAssembly to speed up many existing web apps,” said Nick Nguyen, Vice President of Product, at Mozilla.

"Compilers like Mozilla’s Emscripten can target the WebAssembly virtual architecture, making it possible to run portable C/C++ on the web at near-native speeds. In addition to C/C++, the Rust programming language has preliminary support for WebAssembly, and LLVM itself includes an experimental WebAssembly backend," said Mozilla engineer Dan Callahan. "We expect many other languages to add support for WebAssembly in the coming years," meaning developers will be able to compile web pages to WebAssembly format regardless of the programming language they wrote the code in.

For starters, WebAssembly is only included with the desktop version of Firefox 52. Other browser makers are also expected to add support for WebAssembly in their official branches as well.

Other Firefox 52 changes

Besides adding support for WebAssembly, Firefox 52 also comes with various other changes. The easiest one to notice is the addition of “in-your-face” warnings when trying to log in via insecure HTTP pages.

Insecure login warning

The other major change in Firefox 52 will only be spotted by laptop and smartphone owners who roam daily from WiFi network to WiFi network.

The change is related to “captive portals,” a name given to the websites that WiFi users must access and register/authenticate, in order to use that network.

In situations where the WiFi network is improperly configured, Firefox 52 will step in, discover the captive portal URL and through a notification bar, offer to help redirect the user.

Captive portal warning

Changes in Firefox 52, related to the browser's built-in developer tools are detailed in depth on the Mozilla Hacks blog.

Furthermore, Firefox 52 is also an ESR (Extended Support Release) and will be the last one to support Windows XP and Windows Vista users. Mozilla is expected to announce end of support for the two operating systems in September 2017.

Also previously announced, Firefox 52 will also disable all browser plugins (different from add-ons) that work on the old NPAPI platform, with the exception of Flash.