Internet Explorer 9: Emphasis on energy efficiency
Of course, there's no easy way to test this assertion, even with an electrical meter because the computer could be burning electricity on some background task. However, the idea is meaningful, in large part because handheld devices need to be very careful with power consumption. While no one really notices if their video card on the game machine requires a separate pipeline from the Middle East to keep it running, everyone squawks when the phone dies halfway through the afternoon.
IE9 does not yet run on phones, but it may affect laptop energy conservation. Furthermore, simply paying attention to browser energy consumption may put Microsoft ahead of what could soon become a very important game.
Chrome: A separate process for each tab
For the past few years, interest in multiprocess architectures has been growing among browser developers. Here, Google has taken the lead, splitting the work of Chrome tabs into different processes. This approach relies on the operating system to isolate crashes, thereby making the browser more stable. In other words, if one plug-in or Web page goes south, the OS isolates the danger, usually ensuring that the other tabs sail on unaware.
Of course, all browser makers are rolling out multiprocess technology in different ways and at different speeds. Open your PC's process display window and start cracking apart the tabs -- you'll see that the browsers spawn a few processes, but only Google Chrome keeps opening them up. Chrome is the browser most committed to separating the workload and letting the operating system act as a referee.
Some argue that this belts-and-suspenders approach is overkill and not worth the overhead, claiming that the browser makers should not fall back on the operating system for support. Others suggest the browser experience can end up being slower if related windows are split into different processes. To combat this, Chrome sometimes puts pages from the same domain in the same process, but you can expect arguments over the best way to handle multiprocessing to continue for the foreseeable future.
Internet Explorer 9: Jump lists and site pinning
Jump lists began as little menus attached to icons in Windows 7. Right-click an application's icon and you'll find shortcuts to app-specific tasks and recently accessed files as determined by the app's developer. Now these jump lists are part of IE9, and every Web designer can specify a quick list of important pages for users to access quickly with a right-click. IE9 takes the jump-list concept one step further by allowing you to "pin" websites to the bar at the top of each window where they can be easier to reach. The jump list adds a pull-down menu for these pinned websites. It's a good solution for common destinations, like email or shopping sites.