All bugs mentioned in this post are now fixed . Internet Explorer has a number of features designed to render pages more quickly. One of these features is called the "Lookahead Downloader" and it's used to quickly scan the page as it comes in, looking...

Protocol Restriction Internet Explorer's native XMLHTTPRequest object permits requests to HTTP and HTTPS only; requests to FILE, FTP, or other URI schemes are blocked. Update : IE10 XHR supports CORS . Method Restriction The object permits only the...

In general, IE8 is a significantly faster browser than prior versions. We made a number of major investments throughout the browser’s code to help ensure that IE users will have a great real-world experience on the web. However, it is definitely the...

Some time ago, I wrote a summary of how Internet Explorer’s cache works . At the time, I left out mention of the two cache-control directives introduced by IE5: pre-check and post-check . These directives enable a “background update” mechanism where a...

When evaluating the security of Internet Explorer’s ActiveX support, there are two threats to consider: · Malicious controls · Malicious websites To mitigate the threat of malicious ActiveX controls (malware), features like the IE8 SmartScreen...

Often, folks ask us why we continue to support IE6. The short answer is that because we've committed to doing so . But more importantly, even if we dropped support, most people who want to use IE6 would still use it anyway, just without the benefit of...

I had someone ask me for help writing a Proxy AutoConfiguration script today. PAC files are basically simple JavaScript files that expose one function, FindProxyForURL(url, host) . The function returns a string containing a list of one or more proxies...

Q: Eric, you mentioned that the IE8 Web Browser Control, hosted in Forms / WPF, runs in IE7 emulation mode by default. Is there a way to turn the emulation mode off and have the control work in "real" IE8 mode? A: Yes. This is controlled by a feature...

RFC 2616 describes the Accept request header as follows: The Accept request-header field can be used to specify certain media types which are acceptable for the response. Accept headers can be used to indicate that the request is specifically limited...