If the concept of Mobile Java has you scratching your head and pondering cups of coffee on the run, read our guide to what's what in the world of mobile programming environments.

At the International Consumer Electronics Show in January, Microsoft founder Bill Gates discussed Moore's Law, which postulates that computing processors were doubling in power every two years.

Another way of looking at it, he said in his keynote, was that the chip required for a "particular level of richness" would drop by half every two years.

"And so this means that we can take microprocessors and put them everywhere. Now, for US$4 to US$8 the kind of intelligence we get in the microprocessor is far beyond the original PC," he said.

He concluded that smart devices would be common, and that this was a "real mindset change for the hardware industry" as software will be required in all kinds of devices. Gates' observation is echoed in Microsoft's move into smart phones and mobile devices.

Indeed, as phones become more and more powerful, it is possible today for a user to download an application that translates a foreign language or tells the weather. Alternatively, he might choose to download a high-quality, colorful game from the Web.

Java allows users to do just that.

Java fundamentals

Java technology was invented by Sun Microsystems in 1995 as a complete environment for developing and running Java-based applications. Although its original appeal was in bringing animation to Web pages, it quickly became employed in both desktop and enterprise applications.

In December 1998, Sun announced Java 2 with three different versions, including Java 2 Standard Edition for desktop-based applications, and Java 2 Enterprise Edition for (J2EE) for server-based applications.

The third is the Java 2 Micro Edition (J2ME), targeted at machines with less power than typical desktop and server machines, such as cell phones, PDAs and consumer electronic devices. J2ME is further subdivided into different profiles, with the one for cell phones called "mobile information device platform," or MIDP.

Java's appeal is in its "write once, run anywhere" philosophy, which theoretically lets one program run on different software and hardware platforms. On desktops, this means that a gaming client can run on both Mac or Microsoft operating systems. On mobile phones, this allows the same chat application to be used on a Nokia, Motorola or Siemens handset.

Java's promise of universality has contributed to its adoption by the Open Mobile Alliance, which aims to deliver open standards and specifications for the wireless industry. This alliance, which comprises almost 200 members including phone makers Nokia, Motorola and Sony Ericsson, has identified Java as a key technology.

Coming to a phone near you

Wireless Java has a significant footprint in handsets, especially in Japan, where NTT DoCoMo launched its J2ME i-appli service more than two years ago. By the end of January 2002, the number of i-Appli phones in Japan had hit 11 million.

Outside Japan, many of the world's largest phone manufacturers are also making a charge this year. For instance, most of Motorola's announced handsets will come with J2ME, including the third generation (3G)- capable Motorola A820.

Nokia, the world's largest handset maker, has also predicted that it will ship 100 million Java- enabled phones by 2003.

A different BREW

A challenger to Java is Qualcomm's Binary Runtime Environment for Wireless (BREW). Proponents of BREW say that this technology is built into the chip of the phone itself, so applications can run faster than Java.

This is also where Java's strength becomes its Achilles' Heel. Java-enabled devices come with an additional interpreter called the Java virtual machine (JVM). The JVM translates the application's programming code for each individual device, thereby ensuring platform independence. However, this JVM takes a toll on performance.

According to Danielle Jones, director of business development at technology firm TTPCom, this is a significant stumbling block in processor-intensive games. TTPCom has developed a graphics engine that, by harnessing BREW, improves the performance of handsets.

She also pointed out that despite the universality mantra touted by Sun, Java applications are not fully interoperable. Something written for a Nokia, for instance, will not work with a Sony Ericsson phone. This is due to the different application programming interfaces (APIs) used by each manufacturer, she said.

To that, Sony Ericsson's Jose-Maria Bescos, senior manager for Global Product Marketing, argued that while the problem exists, it is still relatively easier for developers to tweak their applications to suit various J2ME-compliant handsets.

While the battle between Qualcomm and Sun is still going on, some analysts are already predicting a winner.

"Java will eventually win out," said Michael King, a senior wireless application analyst at Gartner Dataquest.

Sun is also responding to J2ME's performance concerns. It is currently working on a project called "Monty" to speed up the performance of JVMs by a factor of five to 10.

The search for developers

One of the key challenges that J2ME faces is the limited availability of applications.

Tackling this issue, several companies in Asia have come together to encourage developer communities. For instance, the Asian Java Mobile Challenge is organized by SingTel and Sun, and supported by Motorola, Nokia, Siemens and Sony Ericsson.

But an industry insider revealed that J2ME content development in Asia was plodding along slowly, with a vicious circle possibly in place: developers are looking for consumers to show interest in Java applications, while end users are waiting for the right app to come along first.

If there is a killer application, what would it be? In a view that reverberates across the industry, Siemens Information and Communication Mobile senior vice president Georges Boulloy said last year that on a global level, gaming will be important for application downloads.

Conclusion

There are many pieces to the Java puzzle, from mobile operators and phone makers to developers and end users. It also comes at a difficult time for the industry. Global sales of mobile handsets has been stagnant, while some industry players are understandably wary after the well-documented problems of the mobile Internet.

That said, Java is based on a simple premise. With the convergence of mobile communications and computing technologies, customizable applications is a natural step in the evolution of mobile phones. Just as users today scour the Web for applications and games for their desktop computers, mobile phone users may one day do the same.