Transitive Technologies confirmed Tuesday that it is providing Apple with technology that allows old Macintosh software programs to run on computers based on Intel rather than IBM chips. Transitive's technology will be part of software called Rosetta, which will work for current Macintosh OS X programs that run on PowerPC systems but not for older programs that run on OS 8 and OS 9 software, according to Apple.

Rosetta will be important for Apple to hang onto its loyal Macintosh customers at a time when it is making a major switch to new hardware. If Rosetta lives up to its promise, consumers won't have to throw away their old software when they buy a new computer from Apple with Intel chips.

Transitive's technology is the result of years of effort. In 2000, Transitive was formed by researchers at the University of Manchester in England. They had developed a way to do ``binary translation'' at high speeds. Transitive has raised $24 million to date.

The software consists of three parts. One part is a decoder, which takes the code of the older software and converts it into an intermediate format.

The second part is the core processing engine, which Wiederhold calls the ``secret sauce.'' The core takes the intermediate format and figures out how fast it can run the older software in its new form.

The third part is custom-tailored to convert the software into a form that runs on the target computer. This software sits on the computer, in this case an Apple computer that uses Intel chips. Whenever a consumer clicks on an old Apple program loaded onto the computer, the translation software starts. It translates and leaves the final code stored in the system's main memory chips. If the consumer uses that software again, the machine can run the translated code from memory.