Opera Software has "expressed significant doubts it would continue producing a browser for the Macintosh operating system," reports ZDNet News. It is worried about the Safari browser, which Apple can bundle with its monopoly hardware. "The Mac platform may not be viable for us any longer," said Jon von Tetzchner, Opera's chief executive. Comment: All operating systems grow over time, and add popular features that used to be provided separately. (On PCs, things like typefaces and networking used to be separate, for example.) The problem is the small size of the Mac market. You can get rich on 5% of the Windows market, but 5% of the Mac market may not be worth the effort.