Rather quietly, there's yet another revolution in computer technology going on – one that may bring about the kind of global democratization that enthusiasts have been predicting for so long. It's the incredible shrinking computer. There are those who envision the day when every schoolchild on the planet will have one, creating a flood of new, youthful interest in programming.

During our lifetimes, many of us have watched the computer evolve from a big, clunky mainframe, with its spinning tape reels and instructions arriving via punch cards, to a compact unit (which most people forget was originally called a microcomputer) that fit neatly on every desktop, to a battery-run laptop that you can take anywhere, and on down through various, ever-smaller devices like tablets and smartphones that share some but not all characteristics with computers.

The next logical step would be a full-featured computer, with real power and programmability, that is super-cheap and fits in the palm of your hand. A sub-microcomputer, if you will. That step has been taken.

The big splash in this area was made in early 2012 with the commercial debut of the British-based Raspberry Pi, which will come in two models, A and B, selling for US $25 and $35, respectively. Model B is the only one available at the moment, with Model A scheduled to begin shipping in the first quarter of this year.

The Raspberry Pi

Both versions come with a Broadcom BCM2835 system on a chip (SoC), which includes an ARM1176JZF-S 700 MHz processor (which can be souped-up to 1 GHz without impairing the lifetime of the machine), a VideoCore IV GPU, and 256 megabytes of RAM that was later upgraded to 512MB. There is no hard disk nor solid-state drive; the computer uses an SD card for booting and long-term storage. Both have audio and HDMI video outputs.

The Model B has two USB ports and a 10/100 Ethernet controller. Model A has a single USB port and lacks the built-in Ethernet controller, but it can connect to a network through a user-supplied USB Ethernet or Wi-Fi adapter.

Fedora Linux is the free, open-source operating system that's used by default in the Raspberry Pi. But after users reported bugs in Fedora, Raspbian, a Debian-based OS optimized for the Raspberry Pi hardware, was released in July 2012 and is the current recommended system.

That's a pretty impressive lineup of features for something so small and inexpensive – and the initial demand reflected that. Interest ran so high in the first days that it stalled the sites of the shops selling the computers. Moreover, that demand has proven durable. Premier Farnell, one of the two authorized manufacturers of the product (RS Components is the other), announced in January that it has sold more than a half-million units. RS Components, which took 100,000 pre-orders on day one, is apparently selling them equally briskly, so it's likely that there are now a million of the devices out there.

Such a number is mind-blowing to chip architect Eben Upton, co-creator of the little PC. "We honestly did think we would sell about 1,000, maybe 10,000 in our wildest dreams," he says. "We thought we would make a small number and give them out to people who might want to come and read computer science at Cambridge."

Those 10,000 Upton thought he'd sell all told? Gone in the first couple of hours.

While the Raspberry Pi Foundation – a charitable body initially funded by loans from Upton and five other trustees – was established with the intent to "educate and encourage a new generation of computer scientists and to invigorate computing in the UK and beyond," it was no time at all before DIYers everywhere began devising all sorts of other applications. Among other things, it's been used: to stream 1080p video; as a home-automation controller; to run photo/video picture frames around the house; to operate a video camera on a quadcopter UAV; and to maintain proper temperature levels in a beer-brewing operation. One ingenious person wrote on Reddit that his is functioning as a "kitchen computer. With a barcode scanner close to the trash can, so we can add items to the grocery list when something runs out." And a project called FishPi aims to use the tiny PC to guide an unmanned boat across the Atlantic.

For the more technically minded, anyone who really wants to dive into programming will find online a free Cambridge University course that teaches how to develop your very own Raspberry Pi OS.

There's also an app store. The Raspberry Pi website announced in December that it was launching "the Pi Store to make it easier for developers of all ages to share their games, applications, tools and tutorials with the rest of the community." Twenty-three free titles were made available as part of the store's introductory inventory, including LibreOffice, Asterisk, Freeciv, OpenTTD, and Iridium Rising.

That community is a growing part of the Raspberry Pi's appeal. People are developing fanzines around the platform. Raspberry Jams – meetups of owners and enthusiasts, who gather to share stories, swap ideas, and generally work out what to do with their new devices – sprang up almost immediately in Britain. The idea then quickly spread to much of Europe, along with the US, Canada, Australia, and Singapore.

Raspberry Pi's low cost is bound to bring out any number of philanthropists and other buyers willing to give them away. For starters, Google – OK, undoubtedly sniffing profit somewhere down the road – just announced that it is donating 15,000 of the computers to schools in the UK.

Naturally, anything that has had the kind of success that Raspberry Pi has is bound to spawn a host of competitive products. So it's hardly a shocker that the sub-microcomputer market has exploded.

Last summer brought the Oval Elephant. It costs $72 and comes with Android 4.0, but can run Linaro Linux as well.

A microSD card slot supports up to 64GB, and a full HDMI port enables direct connections to a TV or monitor. The device is powered via a mini-USB port, and it also features built-in MIC and an external port for MIC audio.

A single-core 1.5GHz AllWinner A10 Cortex A8 ARM processor runs the device; 1GB of DDR3 high-capacity memory is included, as is WiFi connectivity, a MALI400 graphics processing chip, and 1080p HDMI video output, with support for 2160p.

Next up was the Mini X, retailing for $79, powered by the same AllWinner A10 processor.

It can reportedly run a variety of Linux distributions, including Ubuntu, Fedora, and Puppy Linux. With support for both Android 2.3 and 4.0, the Mini X features 512MB of DDR RAM, 4GB of Nand Flash, a microSD slot, an HDMI port, and WiFi 802.11b/g/n with an external antenna. It plugs into a TV, where you can then run apps to your heart's content; a remote is included.

Then in September we saw the introduction of two new entrants into the under-$100 space.

Cubieboard, created by a Chinese team, was birthed through crowdfunding on the Indiegogo.com site. Aptly promoted as a "Raspberry Pi on steroids," the Cubieboard sells for just $49 and offers a 1 GHz ARM processor, Mali 400 graphics, a gigabyte of RAM and 4 gigs of flash memory. It can run Android, Ubuntu, and a variety of other Linux distributions. It has Ethernet, HDMI, and USB ports, as well as a built-in SATA port that lets it power a hard drive all on its own.

At about the same time as Cubieboard appeared, South African distributor Reno Botes introduced the MK802, which sells for $74.

It's very similar to the Cubieboard, except that its processor is a dual-core ARM A9. In addition, it runs Android 4.0 Ice Cream Sandwich and includes access to the Google Play Store, which makes downloading apps simple.

Finally, in November, Bulgaria-based Olimex trotted out the A13-OLinuXino, selling for $57. It comes with an Allwinner A13 Cortex A8 processor running at 1GHz, along with a 3D Mali400 GPU and 512 MB of RAM. Four USB hosts are built-in – with one dedicated to WiFi – as is an SD card connector, VGA video output, audio output, five keys for Android navigation, and a UEXT connector for modules such as Zigbee or Bluetooth. Also available is an optional low-cost 7-inch LCD with touchscreen. Android 4.0 is included, but it's also possible to run Debian and other Linux distributions, Olimex says.

As you can see, while Raspberry Pi remains the price leader, those wanting a bit more computer are able to select among a number of entrants available for a bit more money.

So what's the takeaway from all this?

It just might be that manufacturers of these microdevices are sowing the seeds for the next crop of young hackers (who will increasingly come from the developing world, as all of its nascent talents are released). Traditional PCs may soon be regarded like the mainframes of old, and vast networks of tiny, interconnected devices like this could be the next big leap forward.

Super-cheap chips, ubiquitous wireless, small form factors, open sourcing, and a large and creative community all are coming together to support the ongoing computer revolution, which never stands still.

Bits & Bytes

What's Next in Wearable Computers? (San Francisco Chronicle)

It just might be the SmartWatch. Google is actively exploring the idea of making one, Apple has been rumored to be doing the same, and a company called Pebble – which smashed crowdfunding records on Kickstarter by pulling in $10M – is about to ship its version. Some observers think the device could eventually replace the smartphone, finally landing us in Dick Tracy territory three-quarters of a century after the comic-strip detective started talking to his wrist.

Same Old, Same Old for RIM (Globe and Mail)

Research in Motion has appointed Alicia Keys to be its new global creative director. Oh, and it also released the Blackberry 10 to a wealth of rave reviews. Neither apparently impressed investors, who pounded the company's stock price, knocking it back 20% in a day and a half.

Surface Off to a Rocky Start (Computerworld)

Microsoft's Windows RT Surface tablet is off to an exceedingly poor start, with sales of at most 750,000 and very high rates of return, according to Rhoda Alexander, an analyst at iSuppli. Alexander attributes the return rate to the steep learning curve of the Win 8 OS, and she notes that there is a "distinct lack of interest" among hardware makers – including Acer and Samsung – to build RT-based devices.

Hike the Grand Canyon from Home (PCMag)

If you've always wanted to hike the Grand Canyon but lack the physical or financial means, Google announced today that it has added more than 9,500 panoramic images of the canyon to its Maps service. The interactive images cover more than 75 miles of trails and surrounding roads.