If you're a web developer, you'll definitely want to browse through Microsoft's document of browsing-related changes in XP SP2.
For starters, there is the IE popup blocker. Popups will be allowed if opened by a link clicked by the user, but other than that, no more JScript window.opens for untrusted domains. By the way, a likely side effect is a rush towards interstitial advertising ("you will be redirected to the requested content after watching these ads for 5 seconds") as popups start losing their effect.
An equally drastic change is the new set of limitations on popup window size and positioning. Popup windows can no longer extend above the top or below the bottom of the parent control, and they must overlap the parent window horizontally. They will stay with the parent window if the parent moves, and they will always appear above their parent windows - so no more hiding or faking dialog boxes. I'll just quote some of the most important other rules:
"Windows that are outside the viewable screen when they are opened are positioned onto the viewable area."
"Windows that are larger than the viewable screen when they are opened are resized to the viewable area."
"Scripts cannot move a window off-screen"
"Scripts cannot resize windows such that the title bar, address bar, or status bar cannot be seen."
"When creating a window, the definition of the fullscreen=yes specification is changed to mean “show the window as maximized,” which will keep the title bar, address bar, and status bar visible."
"Internet Explorer has been modified to not turn off the status bar for any windows. The status bar is always visible for all Internet Explorer windows."
In addition to popups, security zones have a bunch of new tweaks thrown in. Add-ons can be easily disabled. And to introduce another breaking change, "the Internet Explorer will now attempt to rename downloaded files in the Internet Explorer cache to have matching content types and extensions to protect against files that mislead the user about their type."
Most of the changes are pretty irrelevant for legit applications, but in case you had a web UI that was designed to be shown in a small window and then open up image thumbnails (or news articles or whatever) in a larger popup, you're probably in for a redesign - preferably a quick one. Another likely breaking scenario involves quirky webmail apps relying on setting MIME type to application/octet-stream to force download (instead of inline opening) of attachments.
It'll be interesting to see the amount of web apps that'll blow up when SP2 starts spreading. And it feels so good to have Firefox installed. :-)
Posted by Jouni Heikniemi at August 10, 2004 08:58 PM