Internet Explorer 8 for Developers

Introduction

Since its release in March 2009, Microsoft Internet Explorer 8 has made it easier than ever before for you to build and maintain sites that reach and maintain contact with your customers. Built-in developer tools make it efficient and easy to develop and debug your site.  New extensibility capabilities let you differentiate your site and keep customers coming back.

• Create rich sticky experiences
• True and accurate standards support. Code once. Run everywhere
• Great tooling support right out of the box

In this paper, we will take a look at the enhanced Internet Explorer 8 feature set, compatibility with previous versions and some topics relevant to developers.

Enhancements in IE8

User Features at a Glance

Being Compatible with Compatibility

When Internet Explorer 6 was released in 2001, it was considered a state of the art web browser that was more standards compliant than it's competition at the time.  It gained widespread acceptance as the most used browser in the marketplace. Since then the browser market has changed drastically, and Internet Explorer 6 is barely considered a modern browser.  While usage share of Internet Explorer 6 has dropped significantly, it is still used, and developers still have to work with it's many intricacies.  In the resulting years since Internet Explorer 6 has been released, the browser vendors have evolved with standards and created more and more compliant browsers.

IE7 was released in 2006 and contained some highly anticipated features that enhanced the user experience, such as tabbed browsing, but also enhancements to better support web standards.

However, it wasn’t until the release of Internet Explorer 8, in which one of the major focuses was on a much stricter compliance with web standards, that it became fully compliant with the Cascading Style Sheets (CSS), Level 2 Revision 1 (CSS2.1) specification and now supports some features of CSS, Level 3 (CSS3).

Internet Explorer 8 Compatibility Features

Internet Explorer 8 introduced a new concept in web compatibility.  Rather than forcing developers to update their sites with each new release of a browser, that fixed rendering or layout issues, Microsoft offered developers a way to choose from a known set of rendering engines.  Internet Explorer 8 can render sites with it's new rendering engine, or they can choose from the Internet Explorer 7 rendering engine, and finally the Quirks mode engine.

Using this method, developers only need add a simple META tag to their page, or set the flag via an HTTP response header.

By default, Internet Explorer will always use the latest version of the rendering engine, and will only use one of the less standards compliant engines if it is told to by the user, the developer or by Microsoft.

As a web site developer, you can choose a method by which you ensure the compatibility and continued rendering of your site in the IE8 environment:

Best Practices for Compatibility Moving Forward

1. Use the <meta> tag content attribute:
2. <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />
3. Use IE=EmulateIE7 for legacy and old websites
4. Use IE=EmulateIE8 for new and actively maintained websites
5. Test your site on Internet Explorer 8, 7, and 6
6. Identify site elements that may not work the same in IE8, even with the compatibility tag
   • XSS (Cross Site Scripting) Filter– prevents JScript from executing. The XSS Filter operates as an IE8 component with visibility into all requests / responses flowing through the browser. When the filter discovers likely XSS in a cross-site request, it identifies and neuters the attack if it is replayed in the server’s response. Users are not presented with questions they are unable to answer – IE simply blocks the malicious script from executing.
   • JSON function calls
   • DEP/NX option – Data Execution Prevention (DEP) or No-Execute (NX) prevents code from running in non-executable memory. This protection applies to both Internet Explorer and the add-ons it loads. With DEP/NX the Windows Kernel monitors a program's execution. If the Kernel detects an attempt to run code from a memory page that is not marked executable, the Kernel halts execution of the program, resulting in a "crash." This is a security measure to help ensure that memory-related vulnerabilities (for example, buffer overflows) in the application cannot be exploited in order to execute arbitrary code.
   • ACT (Application Compatibility Toolkit) helps customers understand their application compatibility situation by helping identify which applications are compatible with Vista, IE7, and IE8 and which require further testing. ACT allows compatibility data to be uploaded from individual machines to a central location for analysis, grouping and reporting. Once an issue has been identified, help will be available on how to resolve a particular issue or create a workaround. Furthermore, partners and customers using ACT are able to post comments to the Online Application Community, where they can share data and information about application compatibility testing.
7. The IE components of ACT are:
   • Internet Explorer Compatibility Test Tool (IECTT). The IECTT helps identify your Web-based issues, shows your results in real time, and allows you to upload and view the data in the Application Compatibility Manager (ACM), a part of the ACT toolkit. As you test your application or site, the IECTT records events in real time when compatibility issues occur. For instance, if one of your sites injects JavaScript to another site and the IE8 Cross-site scripting (XSS) filter detects this as a reflection attack, a Cross-Site Scripting Filter event would be logged in the IECTT UI.
   • Internet Explorer Compatibility Evaluators (IECE). The IECE can be deployed within an enterprise and will help identify Web-based issues in the background. As you test your application or site, the IECE records events in the background as they occur. You will be able to view the logged events in the ACM after you upload them.

Overall, these tools help customers lower their costs for application compatibility testing, prioritize their applications, and deploy Internet Explorer more quickly.

Just for the Developer

Summary

Internet Explorer 8 is a major release in every sense of the term, across the board. Microsoft has incorporated popular features, adhered to leading standards, made security a priority and created a rich platform with developers in mind. Internet Explorer 8 makes it easier than ever for you to build and maintain sites that reach and connect with your customers like never before.

References

• Features List - http://www.microsoft.com/windows/internet-explorer/features/faster.aspx
• CSS Improvements in Internet Explorer 8: http://msdn.microsoft.com/en-us/library/cc304082(VS.85).aspx
• Defining Document Compatibility: Step-by-step instructions for meta tag placement at http://msdn.microsoft.com/en-us/library/cc288325(VS.85).aspx
• IE8 Compatibility – Meta tags, HTTP headers, User Agent Strings on from Mike Ormond's (DPE) Blog at http://blogs.msdn.com/mikeormond/archive/2008/09/25/ie-8-compatibility-meta-tags-http-headers-user-agent-strings-etc-etc.aspx
• ACT (Application Compatibility Toolkit) 5.5 with the IE Compatibility Test Tool at http://www.microsoft.com/downloads/details.aspx?familyid=24DA89E9-B581-47B0-B45E-492DD6DA2971&displaylang=en
• Application Compatibility Toolkit 5.5 Application Compatibility Whitepaper at http://msdn.microsoft.com/en-us/library/dd565632(VS.85).aspx
• Internet Explorer 8 Compatibility Test Guide at http://msdn.microsoft.com/en-us/library/cc848857(VS.85).aspx
• Internet Explorer Compatibility Center at http://msdn.microsoft.com/en-us/ie/cc405106.aspx
• Internet Explorer Developer Center at http://msdn.microsoft.com/en-us/ie/default.aspx
• Internet Explorer 8 Readiness Toolkit at http://www.microsoft.com/windows/internet-explorer/readiness/default.aspx
• Internet Explorer 8 Home Page at http://www.microsoft.com/windows/internet-explorer/default.aspx
• http://www.microsoft.com/windows/internet-explorer/developers.aspx