Microsoft today shared a list of legacy IE technologies and features that are not part of Microsoft Edge. Over 220,000 lines of code in MSHTML have been removed from Microsoft EdgeHTML which will lead to better interoperability with other modern browsers, improved performance, security & reliability, and reduced code complexity, and more. Find the list below.
These technologies will continue to be supported in Internet Explorer on Windows 10 for users and enterprises who depend on them.
|Technology||Why it existed||Why we don’t need it anymore|
|ActiveX||ActiveX is a binary extension model introduced in 1996 which allowed developers to embed native Windows technologies (COM/OLE) in web pages. These controls can be downloaded and installed from a site and were subsequently loaded in-process and rendered in Internet Explorer.||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.To enable extensibility beyond what is provided by HTML5, we are working on plans for a modern extension model in Microsoft Edge. We look forward to sharing more details on these plans soon.|
|Browser Helper Objects (BHO)||BHOs are a binary extension model introduced in 1997 which enabled developers to write COM objects that were loaded in-process with the browser and could perform actions on available windows and modules. A common use was to build toolbars that installed into Internet Explorer.|
|Document modes||Starting with IE8, Internet Explorer introduced a new “document mode” with every release. These document modes could be requested via the x-ua-compatible header to put the browser into a mode which emulates legacy versions.||Similar to other modern browsers, Microsoft Edge will have a single “living” document mode. In order to minimize the compatibility burden, features will be tested behind switches in about:flags until they are stable and ready to be turned on by default.|
|Vector Markup Language (VML)||VML is an XML-based format for 2D vector graphics, originally proposed in 1998 and originally supported in IE5.||2D vector graphics are supported via Scalable Vector Graphics (SVG) which provides interoperability across modern browsers.|
|attachEvent / removeEvent||IE8 and below supported a proprietary model for DOM events, which supported bubbling but not capture and used a global event object rather than passed as an argument to the event listener.||IE9 and above support the DOM Level 3 Events standard with addEventListener/ removeEventListener.|
|currentStyle||The currentStyle property retrieves the cascaded style of the element.||IE9 and above support the getComputedStyle property (part of DOM L2 standard) to retrieve the final computed style of any element.|
|Conditional Comments||Conditional comments provided a way to embed code that was only targeted at specific versions of Internet Explorer.||It is more effective to use feature detection and other progressive enhancement rather than browser specific code in conditional comments.|
|IE8 layout quirks||IE8 specific layout behaviors that were then emulated in later versions of Internet Explorer.||Most websites are written for standards-based layout. Sites that require IE8 specific behavior on the intranet can be rendered using Enterprise Mode.|
|DirectX Filters and Transitions||DX filters and transitions enabled web developers to apply various visual effects to elements on the web page.||Similar effects can be achieved using standards-based features in CSS3 and SVG.|
In addition to ActiveX and BHOs, there are a number of other legacy extensibility points that are not in Microsoft Edge and will be replaced by a unified, modern extensibility model. These 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
There are also hundreds of other non-interoperable APIs which have been removed. In most cases, these APIs now have interoperable, standardized replacements—removed APIs do not necessarily mean removed capabilities.
Read more about it here.