Even in cyberspace, the moment can only be described as surreal. Two thousand Apple computer loyalists greet the return of their hero and Apple co-founder, Steven Jobs, at a Boston trade show, only to gasp as the looming picture of Apple's archenemy, Bill Gates of Microsoft, appears on a huge on-stage screen. It was Mr. Gates, after all, who copied Apple's visionary point-and-click system of computer commands, marketed it far more aggressively and successfully, and drove Apple to near-collapse.

Mr. Gates and Mr. Jobs announced that Microsoft would inject more than $150 million into Apple and take other steps to guarantee Apple's near-term survival. Some Apple zealots in the audience hooted. Others sighed in relief. Virtually all were surprised and confused. Even in cyberspace it is odd for one company to bail out its only rival in a key area of business. Between them, Microsoft and Apple sell the operating systems, which dictate how computers analyze and display information, that run virtually every personal computer.

Odd or not, the bailout is good for both. Apple users are assured that their beloved company gets desperately needed cash and that Microsoft will continue to supply them up-to-date word processing and other applications software. Many would-be Apple buyers had been turning away out of fear that as Apple's market share shriveled, so would the programs made available for use on Apple machines.

The bailout is also good for Microsoft because it preserves a demand for its software programs designed to be compatible with Apple machines. But some suspect a more Machiavellian purpose by Microsoft as well. Microsoft can now fend off antitrust charges by pointing out that Apple's continued existence will prevent Microsoft from acting as a monopolist. If Apple dies, Microsoft will appear nakedly monopolistic, the only major producer of operating systems for personal computers.