Here are the legacy technologies that were removed in Microsoft Edge

Kareem Anderson

Image Credit: Microsoft

For the past few months, Microsoft has been touting the lightweight design of its new browser, Edge. The browser project formerly known as Project Spartan has undergone some significant changes in order to keep up with modern browsing trends. While IE 11 made some noteworthy strides towards being the browser of the future for Microsoft, the company still felt it needed to do more. With Edge, the browser team went to work ripping apart older technologies and API’s, to the tune of 220,000 lines of code. Removing this amount of legacy was important for the MS Edge team as they attempted to produce a secure, relatively clean and standards compliant browser for the future of Windows.

Today, the Microsoft Edge team is divulging some the reasons for the changes found in the new browser. In a blog post from the Microsoft Edge Dev Blog, the Edge team goes into detail about which items were removed and why they will no longer be supported in the future.

Goodbye ActiveX

The first technology to be removed from MS Edge was the dreaded ActiveX. For a brief history, ActiveX is binary extension model first introduced in 1996. This tool allowed developers to poison embed native Windows technologies in web pages. Eventually, ActiveX became the insufferable tool enterprise used to latch employees to older technologies. With Edge, ActiveX is being left behind. The Edge team explains, “The need for ActiveX controls has been significantly reduced by HTML5-era capabilities, which also produces interoperable code across browsers. Microsoft Edge will support native PDF rendering and Adobe Flash as built-in features rather than external add-ons.”

No more toolbars

Perhaps one of the more understated removals from Edge is the BHO binaries. Finally, web pages will start at the top of the browser rather than being buried under miles of toolbars your parents inadvertently kept installing. BHOs, originally introduced in 1997 as a way for developers to write COM objects that could perform actions on windows and modules, quickly became the toolbar hell IE became associated with. Instead, the Edge team is using modern HTML/JavaScript-based extension models to gain extensibility beyond what HTML5 currently offers. Unfortunately, this model is a work in progress and will have to roll out eventually to the browser.

Image Credit: Microsoft

Stop emulating legacy versions

The document mode found in IE versions dating back to IE 8 will be removed, but the core concept will remain in spirit. Rather than allowing users to drop into a “document mode,” which emulated legacy versions, Edge will enable a “living mode.” This new living mode pushes the browser support forward by minimizing the need for legacy compatibility. According the team, “In order to reduce the compatibility burden, features will be tested behind switches in about: flags until they are stable and ready to be turned on by default.”

Introducing Scalable Vector Graphics

Back in 1998 VML’s helped render 2D vector graphics in browsers. With a technology as old as IE5 being supported but not used, the MS Edge team quickly sought to replace it with a more modern and usable solution. With Edge, 2D vector graphics will be supported by Scalable Vector Graphics (SVG). The SVG provides an interoperability across most modern browsers.

De-facto JavaScript

For better or for worse, JavaScript has become the de-facto language developers write for the web. It’s quick evolution and flexibility are mainly the reasons MS will be saying goodbye to VBScript. The 1996 scripting language is no longer widely used, and development on it isn’t moving as fast as it needs to be. Fortunately, for the Edge team, they have already put to work JavaScript and are already leading to the best implementation of ES6 to date.

No more targeting

Pervious builds of IE used Conditional Comments as a way for developers to emded code that was only targeted at specific versions of IE. Those days are over. The Edge team found it more practical to use feature detection as a solution to browser specific coding. Now website developers can concentrate more on their content rather than spend time building numerous fallback strategies.

Weird layouts are Enterprise Only

Unfortunately, as modern as IE 11 claimed to be, it still carried legacy emulation from IE8 and later. Typically, this resulted in almost every other browser displaying the same layout of a site while IE inexplicably mangled many sites. Edge will be adopting more of the standard-based layout rendering that is currently happening with web pages while allowing specific sites developed for IE8 and later, to be drawn up in Enterprise Mode.

Modern filters and transitions

Back when Microsoft was a juggernaut in browsing, it could influence the adoption of particular technologies. One such technology was DirectX. Developers could leverage DirectX filters and transitions in the browser to apply cool little effects on a web page. Instead of leaning on DirectX, the Edge team is utilizing standard-based features like CSS3 and SVG to achieve similar results for developers.

Image Credit: Windows

There are a few other removals listed by the Edge team in the blog, but those seemed to be them more significant departures. Some others of note include:

  • Binary Behaviors
  • Pluggable Protocols
  • Shell Helper API
  • Active Documents
  • Custom Download Managers
  • Custom Security Managers
  • MIME filters
  • Custom Print and Print Preview Handlers
  • Explorer Bars
  • Edit Designers
  • Timers
  • Accelerators
  • Web slices

The MS Edge team is also removing the necessity for Microsoft prefix versions of APIs like CSS Transforms, Fullscreen API, and Pointer Events. Fortunately enough, many of these have become standards compliant.

It is apparent that Edge has been thoughtfully developed. Much like the new spirit at Microsoft, Edge is willing to shed its long list of requirements in order to be open and accessible. As the Edge team continues to work away on the browser by tearing it down and rebuilding it, it will be interesting to see how other browsers adapt, respond or evolve along the way.