ECMAScript 5 Part 1: Reusable Code

In June, we wrote about IE9’s support for ECMAScript 5 (ES5) and published a TestDrive demo to explore some of the features. With IE9 Beta available, it’s a good time to talk about how developers can use ES5 to improve their code. Many of the features in ES5 are designed to help developers working with…


MIME-Handling Changes in Internet Explorer

Each type of file delivered from a web server has an associated MIME type (also called a “content-type”) that describes the nature of the content (e.g. image, text, application, etc). Back in Internet Explorer 8, we made a few changes to IE’s MIME-sniffing feature that attempts to determine the actual content-type for each downloaded resource….


Testing sites with Browser Mode vs. Doc Mode

With site developers verifying that their sites run well in IE9 and taking advantage of the new HTML5 capabilities and better performance in IE9’s Standards mode, now is a good time to recap how to use Browser Mode and Document Mode to test sites for IE9 and previous IE versions. In summary, developers can use…


DOMParser and XMLSerializer in IE9 Beta

We’ve talked a lot about UI and browser features lately. Today I want to get back to web development by discussing some additions to the platform in IE9 Beta: DOMParser and XMLSerializer. What do they do? DOMParser enables building a document from an XML string and XMLSerializer allows you to serialize it back again. Together…


User Experiences: Evolving IE9 Tabs in Windows 7

With IE9, we wanted to make tabs more useful than ever before.  We know that tabs are a great way to experience multiple sites within a window, and we showed how you can increase the number of tabs possible in IE9’s site-centric frame design.  In IE8, we introduced Tab Groups as a way to help…


“Stranger Danger” – Introducing SmartScreen® Application Reputation

When we released the IE9 beta about a month ago we talked about the importance of trust and confidence when working with downloads. Today, we are enabling the SmartScreen application reputation service to improve download protection for IE9 beta users.  This feature works together with the SmartScreen anti-malware service that protects IE8 and IE9 beta…


The IE Cumulative Security Update for October 2010 is now available via Windows Update

The IE Cumulative Security Update for October 2010 is now available via Windows Update. This security update resolves seven privately reported vulnerabilities and three publicly disclosed vulnerabilities in Internet Explorer. The most severe vulnerabilities could allow remote code execution if a user views a specially crafted Web page using Internet Explorer. Users whose accounts are…


CSS 2.1 Implementation Reports

I want to provide an update to my last blog post about the W3C process that we follow to develop and finalise Web Standards. The working group published the Release Candidate (RC) of the CSS 2.1 Test Suite on September 17. The next step is for the major browser vendors to submit their implementation reports…


Add-on Performance Part 3: Optimizing Add-on Startup Performance

In the first post of this series, we described how add-ons can decrease IE’s performance during tab creation. Many users with add-ons enabled have noticed a performance improvement when they open new tabs after disabling their add-ons. We also walked you through how to measure add-on performance and identify areas of impact using the Windows…