The 10 Most Important Technologies You Never Think About You may not spend much time considering Unicode, XML, and digital signal processing, but you couldn't get through your day without them.

The late sci-fi author Arthur C. Clarke famously said that any sufficiently advanced technology is indistinguishable from magic.

We certainly live in a magical world. We're surrounded by technology, yet we seldom stop to consider the amazing advances that we've come to rely on every day. Whether we're surfing the Web, making a call on our mobile phones, or watching a DVD movie on our big-screen TV, we take our modern conveniences for granted.

Here, then, is a peek inside the magician's hat at ten technologies that are keys to our digital age. Without realizing it, you've probably used at least one of them already today--if not all. But whether you're aware of them or not, without these technologies our world would be a very different place.

Unicode
We use computers for every kind of communication, from IM to e-mail to writing the Great American Novel. The trouble is, computers don't speak our language. They're all digital; before they can store or process text, every letter, symbol, and punctuation mark must first be translated into numbers.

So which numbers do we use? Early PCs relied on a code called ASCII, which took care of most of the characters used in Western European languages. But that's not enough in the age of the World Wide Web. What about Cyrillic, Hindi, or Thai?

Enter Unicode, the Rosetta Stone of computing. The Unicode standard defines a unique number for every letter, symbol, or glyph in more than 30 written languages, and it's still growing. At nearly 1500 pages and counting, it's incredibly complex, but it's been gaining traction ever since Microsoft adopted it as the internal encoding for the Windows NT family of operating systems.

Most of us will never need to know which characters map to which Unicode numbers, but modern computing could scarcely do without Unicode. In fact, it's what's letting you read this article in your Web browser, right now.

Digital Signal Processing
Digital signal processing helps make modern cell phones possible.Digital music, digital photos, digital videos: It's easy to forget that we live in a fundamentally analog world. Computers can cope with all that we see and hear only through the application of highly complex mathematics, a field known as digital signal processing (DSP).

Wherever you find digital media, DSP is at work, facilitated by a whole subcategory of specialized chips and circuits. DSP algorithms correct for errors while your optical drive reads the music off a CD. They're at work again as you compress the audio into an MP3 file, and again when you play it back through your surround-sound speakers.

DSP is to digital media as gears and springs are to a pocket watch. It works its magic below the surface: invisible, yet totally essential. It's safe to say that without it, virtually none of the digital technologies that we take for granted today--from DVDs to mobile phones, ink jet printers to DSL broadband--would be possible.

Managed Code
Microsoft's .NET is a managed code environment.Programming is a lot more complicated than it used to be. Modern operating systems are like onions, with layers upon layers of subsystems to interconnect and manage. Worse, bugs and unnoticed security flaws, even ones that may have once seemed trivial, can be serious threats in the Net-connected era.

For a growing number of developers, the solution is to use platforms designed to relieve some of the burden. Programs written for such managed-code environments as Java and Microsoft's .NET don't run on the bare hardware the way traditional programs do. Instead, a virtual machine acts as an intermediary between the software and the system. It's like a robot nanny for computer programs, silently taking care of memory management and other housekeeping drudgery while keeping an eye out for potential security violations before they happen.

To an end user, a managed-code program may seem no different than a traditional one, but software that runs in a virtual machine makes for a more reliable, stable, and secure computing experience. And with .NET rapidly becoming the preferred platform for Windows development, managed code may soon be the norm, rather than the exception.

Transistors
Later this year, Intel plans to unveil the world's first integrated circuit to contain 2 billion transistors. Moore's Law says that the number of transistors we can put into integrated circuits will double approximately every two years. That's a lot of transistors--but what do they all do?

Simply put, the transistor may well be the greatest invention of the 20th century. It's really nothing more than a voltage-controlled switch, but that humble description hides incredible power. Linked together in various ways, transistors can form circuits that are the basis of every type of digital logic, right up to the CPUs that power our modern PCs and servers.

What makes today's chips so powerful is the industry's ability to cram components ever closer together. The transistors on the processor inside your PC might be only about 100 atoms across, and improvements in manufacturing technology will keep them shrinking--at least, for the time being.

Someday, optical chips or even quantum processors may replace current chip designs and outperform them many times over. For now, we'll have to content ourselves with continuing to improve upon an oft-ignored technology that has served us for 50 years and counting.

XML
You've probably heard of XML, but what is it? Where is it?

Though you may never have encountered it directly, XML is everywhere. Now in its tenth year, it has become virtually the lingua franca of data exchange.

XML stands for "extensible markup language" -- extensible because developers can add to it to suit the needs of particular applications. But what makes it really valuable is the fact that it's a language, much like HTML. Unlike some data formats, XML files aren't just streams of incomprehensible numbers. XML is designed to be read by humans as well as machines. A developer who "speaks XML" can look at a document written in an unfamiliar XML dialect and still understand what it's trying to say.

This powerful combination of features makes XML incredibly useful for all kinds of applications. But perhaps its biggest coup was Microsoft's decision to switch to XML-based file formats for Office 2007. As it turns out, you actually may have XML documents sitting on your desktop right now, without realizing it.

Nonvolatile RAM
Isn't it strange? Your pockets stay the same size, yet you can carry more and more in them every year.

In 1956, IBM's first hard drives used disks that were 2 feet wide. It's hard to believe that today's microscale drives use essentially the same technology. Incremental advances, such as the discovery of giant magnetoresistance and the invention of perpendicular recording heads, have produced staggering results. Between 1990 and 2005, magnetic hard drives increased their storage capacity a thousandfold, putting even Moore's Law to shame.

But even with those astounding improvements, hard drives hit a wall when it came to portable devices. They were still too big and too fragile for many gadgets. Enter solid-state drives based on non-volatile RAM. The technology has been used for storage since the 1970s, but it remained phenomenally expensive until manufacturing processes caught up with the demand. Now it is everywhere: in MP3 players like the newest Creative Zen, and in digital cameras, cell phones, and even some laptops.

Manufacturers aren't sitting still; cutting-edge technologies such as "racetrack memory" could lead to solid-state storage that is smaller, faster, and more reliable than ever.

Lithium Ion Batteries
When we were kids, our toys came "batteries not included." With our grown-up, high-tech toys, on the other hand, the battery is often one of the most important features. As essential as mobility has become to how we use technology, it simply wouldn't be possible if our choices were still limited to D, C, and AA.

The invention of lithium ion batteries was the key. The earliest rechargeables were made with lead--hardly a prescription for portability. But because lithium is the lightest metal, lithium-based batteries can store more energy at a given weight than any other variety. Lighter batteries mean smaller, lighter devices; beginning in the 1990s, you could actually put a phone in your pocket.

Running time remains an ongoing challenge, but researchers have no shortage of solutions. In addition to improved lithium ion batteries that use nanotechnology, a number of battery alternatives are slowly coming to market, including ultracapacitors and fuel cells. In fact, pardon me for saying that battery technology is poised for its next big explosion--and personal technology is sure to advance because of it.

Voice over IP (VoIP)
VoIP made possible the inexpensive long-distance calls that use prepaid calling cards.You've made a few Skype calls and you've looked into digital phone service from your broadband provider, but that's as close as you've gotten to VoIP (voice over IP) technology. Or so you think. In truth, VoIP is revolutionizing the telecom industry, blurring the lines between voice calls and digital networks.

Those prepaid calling cards that offer rock-bottom international rates? VoIP makes them possible. Similarly, a growing number of businesses use VoIP behind the scenes to eliminate long-distance charges between branch offices.

Routing calls over the Internet circumvents traditional telephone company charges, and fewer fees and taxes mean lower prices. Digital calls are easier to direct and manage, which makes them attractive even to traditional telephone companies. Don't be surprised if soon the landline you've lived with forever is replaced by an all-digital alternative--though you'll likely be none the wiser.

Graphics Acceleration
Thought your fancy video card was only good for gaming? Think again. Its graphics processing unit (GPU) is really like a second, highly specialized CPU. When it comes to certain kinds of complex math, its performance puts your desktop CPU to shame.

Until recently, all that power went to waste when you weren't chalking up frags. But computer scientists are finding novel ways to use GPU acceleration to speed up applications off-screen, as well. For example, a Stanford University project-- which uses many PCs around the world acting together as a supercomputer to assist protein folding-related disease research--can offload calculations to the GPU to multiply its performance many times.

Because the kind of calculations used to draw 3D graphics are also applicable to many other problems, GPU acceleration is potentially useful for a wide variety of applications, from math-intensive science and engineering to complex database queries. Newer, even more complex chips--such as nVidia's Aegia physics engine--can do even more. No wonder nVidia has begun working on chips for the workstation market.

Increasingly, your PC's performance won't depend on the speed of any single chip. As AMD and Intel get into the game, expect future desktop CPUs to incorporate CPU and GPU capabilities into a single, multicore package, bringing the best of both worlds to gamers and nongamers alike.

High-Speed Net Access
WiMax provides a greater range of broadband access than does the more common Wi-Fi.Where would we be without fast Internet access? It's easy to forget that just 10 years ago, most of us were still using ordinary modems. The broadband revolution ushered in streaming video, MP3 downloads, Internet phone calls, and multiplayer online gaming. And we owe it all to TV.

In the 1980s, cable companies were promising 500 channels of round-the-clock programming. Cable was poised to become the most important wire into the house; but the telephone companies had an ace up their sleeve. A new technology could push high-frequency signals over ordinary phone lines, which previously had been good only for low-bandwidth voice calls. The telephone companies saw this as an opportunity to offer video on demand and to compete with the cable companies at their own game.

Or so they thought. The plans of the telcos for video on demand dried up by the mid-1990s, but the technology remained. Now called DSL, it had morphed into a high-speed household on-ramp to the Internet. The cable companies followed suit with a comparable technology, and the broadband speed race--for both DSL and cable--began in earnest.

Both cable and DSL still use traditional frequency signaling over copper wires, but new breakthroughs are poised to go mainstream. Fiber to the premises (FTTP) promises lightning-fast network speeds, and WiMax will push broadband into territories that wires can't reach today. As for what applications this next broadband revolution will bring--well, we have only begun to imagine.