Although Microsoft and Yahoo are search partners, Microsoft's Internet Explorer 9 (IE9) may complain that Yahoo's new Axis search add-on is slowing down the browser.
After installing the Axis search extension in IE9 on Windows 7 today, Computerworld found that the next time the browser launched, it popped up a message asking if the user wanted to disable Axis and other add-ons to speed up surfing.
The Axis add-on, which displays Yahoo's new search results motif at the bottom of IE, was at the top of the performance-affecting IE extensions installed on the test PC.
According to Microsoft, Yahoo Axis for IE slowed down IE9'S start-up by 0.07 seconds.
The add-on disabling message is not new or somehow triggered by Axis' installation: IE9 has had the feature, officially dubbed "Add-on Performance Advisor" -- since the browser launched in March 2011. The Advisor regularly shows warning messages when the combined slow-down time reaches a triggering level.
Yahoo launched Axis yesterday, offering a free iOS app for the iPhone, iPad and iPod Touch, as well as add-ons for the desktop editions of IE9, Apple's Safari, Google's Chrome and Mozilla's Firefox on Windows, and the latter three on OS X.
The iOS app is essentially Safari with a custom overlay; Apple restricts browsers distributed through the App Store to only those that rely on Safari as its engine.
Yesterday, a security researcher reported that the Axis add-on for Chrome contained a private key that could be used by anyone to digitally sign browser extensions in Yahoo's name.
Yahoo acknowledged the key problem and has issued a revised Chrome add-on.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is firstname.lastname@example.org.