The idea is to allow people to execute commands with a simple flick of the wrist, rather than navigate through complicated point-and-click toolbars and drop-down menus.
In Opera's Web browser, for example, a person who wants to return to a previous page can simply hold down a button and slide the mouse to the left, rather than moving the cursor to the top of the screen and hitting the "back" button.
Opera's solution first appeared about 18 months ago in Opera 5.11. It has won raves from some of its followers, and now others are closing in on similar versions for a range of other applications.
"We're happy to accept the accolades," said Opera CEO Jon von Tetzchner. "I don't think mouse gestures are going to revolutionise the user interface. But it's a good idea, and it works."
Programmers associated with the Mozilla open-source team plan to release an upgrade this week to a mouse-gestures project known as Optimoz. The effort is one of several to expand the reach of a kinetic, rather than a graphical, user interface (UI) in the browser and beyond. At least one developer is seeking to add gesture functions in popular Windows applications.
While still in development, the Mozilla mouse gestures are already winning fans.
"The tried-and-true, point-and-click method of getting things done still has its place, but I find that for actions I perform often, such as reloading a Web page, making gestures with the mouse is a big win," said David Perry, a programmer at the University of Toronto who was impressed enough to participate in the project.
"The motion of performing a gesture is more natural than sliding the mouse over to a button or menu," he said. "And because it works anywhere in the window (not just on the button), it saves a bit of time and effort, especially as screens get bigger and you have to move farther to reach a button."
Mouse gestures are just one of the latest attempts to improve the PC user interface, which has coalesced around a series of conventions first hammered out by engineers at Xerox's Palo Alto Research Center in the 1970s and subsequently commercialised by Apple Computer to wide imitation.
User studies have long pointed to inefficiencies in the traditional graphical user interface (GUI), and shortcuts around toolbar menus have been available for years. Most applications offer a set of hot keys, for example, that allow people to execute commands from the keyboard rather than the on-screen toolbar.
Increasingly, shortcuts have focused on the mouse, with manufacturers such as Logitech adding new, programmable buttons to simplify common commands with a single click, including the "back" command in Web browsing. Indeed, mouse gestures have been incorporated into some advanced 3D CAD (computer-aided design) programs, but they are now being extended to ordinary computer tasks.
The efforts come as computer makers rethink the whole PC interface with new classes of devices that rely less on the traditional keyboard--or cut it out altogether--such as handhelds and Microsoft's Tablet PC. The touch-screen device, which has handwriting-recognition capabilities, is due out November 7.
Logitech said it is in talks with developers working on mouse gestures technology, although it is not yet ready to disclose potential partners.
"We have been looking at the mouse gesture sphere," said Carol Golsch, software product marketing manager at Logitech. "Many of these projects are still in beta, so it's still a little early for some of these things to come to fruition."
