Avie Tevanian, Apple Computer's recently appointed senior vice president of software engineering, has shed light on the choice of the Mach kernel and given some hints on Apple's current progress on developing its Next-based OS, Rhapsody.
Tevanian says Apple chose to adopt Mach because alternative kernels offered no advantages compelling enough to outweigh the certainty and stability offered by Mach. He notes that Next Software had been shipping different versions of it for more than eight years and that it is well matched to the OpenStep APIs and applications.
Among the alternatives, Tevanian says Nukernel was a better fit in some respects because it ran on existing Macintosh hardware and had wide-ranging driver support. Nevertheless, the work required to add these qualities on top of Mach was not significant compared to the work that would have been necessary to implement Nukernel for Rhapsody.
Some Mac developers have questioned Apple's decision to acquire Next instead of Be Inc., believing they could have more readily built and fielded applications for the Be OS. But Tevanian disagrees, noting that important parts of the Be OS, such as the print architecture, scripting, PostScript support, motion video playback, multilingual support, systems extension architecture and remote access, are not yet implemented.
Developers, he says, can get a good start building Yellow Box applications for Rhapsody by using the OpenStep development environment on an Intel PC. Some modifications will be required for the final version of Rhapsody but these should be minor, he says.
Tevanian is projecting a calm and assured demeanour in his new job. While outsiders may have doubts about his abiloity to meet the milestones set for Rhapsody over the next 18 months, he insists that "I would not have let the announced dates go out if I had not been confident that we could meet them."
He says that while the challenge of delivering Rhapsody might look daunting, it is a familar task for him, having delivered numerous OS iterations and ports to multiple hardware platforms during his tenure at Next.
Although many features of Rhapsody have not been finalised, Tevanian says his group has developed an initial list of features that he believes is fairly sound. Coding is well under way and certain aspects of the OS are already up and running.
Now he is concentrating on building his development organszation, which includes both Apple and former Next staff. No decision has been made on including a mail client, such as NextMail. Apple's efforts are focused on developing more fundamental parts of the OS, he says.