No offence, but your computer is a WIMP.

That is, it uses Windows, Icons, a Menu and a Pointer.

WIMP has been the standard graphical user interface (GUI) for computers for decades. It started in the early '70s in Palo Alto, Calif., in the research department of Xerox, but didn't become popular in personal computers until it was used in the first Macintosh computers released in 1984.

The first Mac also introduced the desktop as a metaphor for interacting with the computer. The computer monitor represents the surface of a desk, where files look like paper documents and are kept in file folders or thrown in the trashcan.

That desktop has persisted, even as computers have grown more sophisticated. The first Mac had 128 KB of memory, no hard drive and could connect to other computers only with an optional external modem. Now a typical computer has more than 8,000 times as much memory, one or more hard drives, one or more CD or DVD drives, and connections to a local network, the internet and devices like digital cameras and music players.

The first Mac also popularized the keyboard-and-mouse combination for controlling computers. If you doubt whether the desktop and mouse were made for each other, ask yourself if you'd rather use your laptop with its built-in trackpad or put it on a table and plug in a mouse.

Computer scientists have called for the end of the desktop and WIMP for years, saying the system of hierarchical folders and icons hinders more than it helps. But even critics of the desktop metaphor concede that it's become so ubiquitous, so natural, that adopting a new one would be like learning Esperanto — a good idea in theory, but for most people not worth the trouble.

Windows and icons haven't changed much over the years, but some high-profile programs are moving away from the traditional menu (File Edit View etc.). Microsoft's new web browser, IE 7, doesn't display a menu unless you turn it on, and the next version of its Office suite of programs replaces the menu with a panel of buttons and icons called a "ribbon."

The desktop, only more real

The development of new ways to interact with computers is much researched at university computer science departments, including the Dynamic Graphics Project at the University of Toronto.

Two researchers at DGP caused a minor online sensation with the demo video of their project, BumpTop, a prototype for a new way to enhance the desktop metaphor, rather than abandon it, by adding a more realistic and physical feel.

Anand Agarawala and Ravin Balakrishnan posted the demo video for BumpTop for a meeting of computer programmers called DemoCamp. Last week, a blog called Google Blogoscoped linked to the video and from there it was picked up on several tech websites, including Gizmodo, Digg and Slashdot.

After all those links to a large video file crashed the U of T server, Agarawala put a low-resolution version of the demo video on YouTube. It became one of the most watched videos on the site that week with more than a half-million views.

BumpTop embraces the desktop metaphor and incorporates a virtual physics engine, NovodeX, which is also used in computer games like Unreal Tournament.

"[The desktop] is everywhere, so there's obviously something to it," said Agarawala. "After 30 years, why not use the advances in technology and research and reapply it to the desktop?"

In BumpTop, icons are represented as tiles. Using the pointer, you can pick up and move the icons as you might expect on a Windows or Mac computer, except on BumpTop, all the icons have shape and mass.

They can collide, bounce or stack on top of each other. They can be tossed around, rather than just dragged and dropped. The icons slide on the surface of the desktop like hockey pucks on a sheet of ice.

As on a real desktop, items on BumpTop can be stacked to show that they go together. Within a stack, icons can be rotated or pulled so that corners and edges stick out, indicating that those files need to be read or are important in some way.

The desktop has walls on all sides to keep the icons from sliding off the edge, but icons can also be stuck to the walls like a document pinned to a corkboard.

BumpTop's use of a generic physics simulator resulted in some unexpected effects and happy accidents.

Agarawala demonstrated how a large window could be turned up on end and used as a shovel to push icons in bulk into a corner. An icon laid flat and stuck to one of the desktop's side walls can be used as a shelf with more icons piled on top. One of the testers for the thesis set a series of icons up on their ends and toppled them over like dominoes.

'There's order in the madness'

Throwing icons around the desktop is bound to create a mess, but BumpTop's creators say that's part of the project's appeal.

Researchers working in human-computer interaction often look at psychological and anthropological studies into the way people work in the real world.

"We rarely ever see a completely tidy desktop," said Balakrishnan. "Clearly there's value in messiness. We're not messy just for the sake of messiness. There's order in the madness."

BumpTop is intended specially for pen-based computers, such as on a tablet PC or a large, digital "whiteboard," where the current desktop metaphor is less than satisfying.

"If you use a current GUI on a tablet, it really doesn't work that well at all," said Balakrishnan. "In fact, most tablet PCs I see … are in standard laptop mode. The pen is put away."

Agarawala said part of the reason that tablet PCs haven't taken off is that it's difficult to manipulate objects in the desktop GUI.

"The fundamental stuff doesn't work. Double-clicking doesn't work. Right-clicking is a pain. Those two things you use 90 per cent of the time in the interface," said Agarawala.

"People tend to doodle with pens," said Balakrishnan. "If I'm doodling, why not allow my interface to be doodle-friendly? The addition of the physics really was to give it a sense of realism, a bit of fun and a bit of the doodle-y characteristic."

Physical and virtual worlds

At the same time, computers have advantages over the real world, especially the ability to sort files and undo actions. The programmers disable the physics in BumpTop when it's convenient; for example, tidy stacks of file icons can't be knocked over by bumping them with another icon.

"There's no point in dogmatically being committed to physics," said Agarawala.

The idea behind BumpTop, said Balakrishnan, was to "get some of the benefits of the physical world while retaining those of the virtual."

While the BumpTop demo video has been popular online, the reaction hasn't all been positive. Many have pointed out that the icons have no filenames on them, making it impossible to tell documents of the same type apart.

The programmers say that BumpTop is a research prototype, not a completed operating system, and adding filenames would be easy to do.

Some critics said that messiness, despite what the research might say, is not something they want to see brought to their computers.

And the criticism on Slashdot included an unfavourable comparison with Microsoft Bob, a notoriously unsuccessful attempt to extend the desktop metaphor to an entire room.

"Yeah, that one hurt," Agarawala said with a laugh, and pointed out that his original thesis on BumpTop has an entire page on why Bob "sucked."