A fundamental change in the design of microprocessors is presenting software developers with a challenge and a huge financial opportunity. Chip makers are no longer racing to have the fastest microprocessor and have shifted their focus away from building chips with a single, super-fast calculating core. Instead, to save energy and reduce heat, they're putting multiple cores on the same chip -- the equivalent of several computers on the same slice of silicon.

The cores run slower but are more energy-efficient, and are designed to break up big chores and work on the separate pieces simultaneously. The resulting technology is ideal for the most demanding multimedia tasks, such as processing large video files, pulling information from multiple databases at the same time, or playing a computer game while downloading music and burning a DVD.

The problem is that many software applications were not written for chips with multiple cores, and the hardware is advancing so fast that the software runs the risk of being left behind. As processors sped up, software developers tagged along by making their programmes faster and faster. But now that chip makers are no longer focused solely on speed, programmers must change their tactics and learn to send instructions to different parts of the chip instead of through a single processing core.Intel Corp and Advanced Micro Devices are making their latest microprocessors with two and four cores, with plans for more in the future.