14 DAY TRIAL // In addition to support for HTML5 <video>, Microsoft also plans to introduce the browser’s new User-Agent (UA) String on top of the Platform Preview release of Internet Explorer 9. And as it is the case for HTML5 <video>, the new UA String will be delivered through an update to the Windows Internet Explorer Platform Preview, which, according to Microsoft, will be refreshed at least once every eight weeks, ahead of the Beta development milestone.
“An important change for site developers to know is that IE9 will send the short UA string by default. This change improves overall performance, interoperability and compatibility. IE9 will no longer send additions to the UA string made by other software installed on the machine such as .NET and many others,” Marc Silbey, IE program manager, revealed.
For the time being, the current Build of IE9 Platform Preview, namely v1.9.7.7.45.6019, continues to send the IE UA String. Microsoft took the decision to deliver IE9’s UA String via a Platform Preview update in order to allow developers to adapt their websites to the next generation of Internet Explorer. In fact, the company is inviting devs to test and adapt their sites to the new IE9 US String, while making sure that no negative impact will be delivered to their current UA logic.
“There are four changes to IE8’s UA string that site developers need to be aware of: application version is incremented from ‘Mozilla/4.0’ to ‘Mozilla/5.0’ to match other browsers. This change signals that IE9 is an interoperable browser. Version token is incremented from ‘MSIE 8.0’ to ‘MSIE 9.0.’ Trident token is incremented from ‘Trident/4.0’ to ‘Trident/5.0.’ IE9 will send the following short UA string without additions made by other software installed on the machine: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0),” Silbey added.
IE9 will be designed to send only the short UA String, in an effort to avoid compatibility problems that were previously reported as being related to long, extended UA strings. “This is interoperable with other browsers, and improves compatibility and network performance,” Silbey said. “Applications and platforms can continue to add to the UA string through the pre platform and post platform registry keys as they did in previous IE releases. IE9 will not change existing registry values.”
Internet Explorer 9 (IE9) Platform Preview is available for download here.