Internet Explorer 9 - New Features

An overview of the new features of Internet Explorer 9

Even the first hand experience of Internet Explorer 9 is sufficient to tell that is going to be a gift for web developers. Along with Windows 7, Internet Explorer 9 can be used for gaining enhanced performance benefit without having them write their websites again. It is far better than the predecessor Internet Explorer 8.

Understanding Browser Performance

Before knowing about the new features in IE9, we need to understand what makes a good browser. There are several sub-systems in the browser that leads to superior browser performance. It includes JavaScript, DOM, HTML parsing, CSS parser, formatting, layout, rendering, BlockBuild etc. Different sites have different requirements and hence the time spent on each of these sub systems. One site might be spending more time in DOM and JavaScript engine whereas other might require time for formatting and layout. For checking the improvement in the overall performance of the browser, SunSpider test is commonly used. When the performance of IE9 preview version was tested, the team found it to be better than Firefox and IE8.

Another test of standard compliance is Acid3 which tests around 100 aspects of different technologies. Preview version of IE9 scores 32 out of 100. These scores are bound to improve as the team is still working on factors like CSS selectors.

Features of Internet Explorer 9

Now that we are aware of improvement in performance of IE9 over IE8, let's see what features have led to this level of performance:

New JavaScript Engine -Chakra

IE team came up with a new code called Chakra. The time that gets wasted by any web application in online running is due to JavaScript. Hence, faster JavaScript engine would mean that the application will run faster. Looking at the demands of people for faster JavaScript engine, this new code was developed. According to the SunSpider JavaScript benchmarks, IE9 is around five times as fast as IE8. Also, Chakra has got valuable features like:

Background compilation- Script engines compile the sections and the methods into the machine before running them. In this case, each method is compiled as it is required. The faster script engines use optimized interpreter for faster compilation of individual sections or methods in the machine. IE9 has fast optimized interpreter to run the pages quickly. It also has a background code generator which compiles the script code before the methods get compiled and pushed into the machine. Thus you get faster running of the script engines along with the higher quality of the codes.
Type optimization- The IE9 script engines use the type representation, polymorphic inline caching along with improved implementation of machine types. All of these techniques are available in modern dynamic language implementations for superior performance.
Fast interpretation - IE9 has a new interpreter with a register based layout that leads to fast execution of the interpreter.
Library optimization- The optimization of JavaScript runtime library of strings, arrays, regular expressions and objects has led to better performance of JavaScript pages and applications.

Hardware Acceleration

IE9 has come with the DirectX family of Windows API's (application programming interfaces). This helps the web developers to move the text and graphic rendering from CPU to graphics card. The graphic card is equipped with Direct2D and DirectWrite APIs. Acceleration of graphics would mean graphically rich and intensive sites would open at a faster speed and use less of your CPU. Direct2D has also led to improved font quality and increased readability with positioning of sub-pixel. Also, the web writer need not rewrite the site to be opened in IE9.

SVG Support

IE9 also has scalable vector graphics which helps in creating powerful and attention grabbing visuals. The SVG features supported in the preview version are:

Basic geometrical shapes such as lines, polylines, circle, rectangle, ellipses and polygons.
Coordinates systems, units and transforms.
Full capability of d-attribute, path element and colors.
Document structure, styling and scripting.
Metadata and extensibility.

All of the above make the browser an attractive choice for web developers.

HTML5

We know that HTML is the code on which everything on the net runs. HTML5 is the new and most powerful edition of this code. Along with the features line Cross document messaging, Ajax navigation, DOM storage, ononline and onoffline event handlers that appeared in IE8, HTML5 also has selection APIs element in IE9. This will help IE keep up with the trends that are set with the existing set of web browsers of increasing browsing speed and quality.

HTML5 has improved HTML parsing of generic elements and overlapping tags. This has also improved parsing changes from script to script blocks, parsing SVG in HTML and parsing XHTML.

CSS

CSS (Cascading Style Sheets) is a style sheet language used to describe the look and formatting of any web pages. IE9 has included several feature of CSS3. CSS2, which was included in IE8, had several complains. Improvements have been done in that direction and the new features of CSS3 added in IE9 are:

Backgrounds and borders module- The preview version includes much demanded border-radius properties so that the developers can curve the border corners by specifying the radius.
Color module- IE9 has a better planned color module with the RBGA color model and opacity (controlled transparency at every level) property,
Namespace selector module- This defines the syntax for the use of namespaces in CSS. It is included in the preview version of IE9, however much more is to be included in the future release.
CSS3 selectors- They help the web designers in selecting nodes and hence styling complex documents.

Features Still Missing

Though IE9 is a good product, especially for web developers, experts feel that there are some features of HTML5 missing in the browser. These features are present in Firefox and Chrome. This includes open web front support, Ogg Theora for videos instead of the existing H.264 codec, web workers and canvas elements. There is another disappointing bullet in the announcement regarding the Windows XP users. It says that IE9 can only be installed if you have Windows Vista or Windows 7. It will not work on Windows XP version.

- Staff, 2010/01/22