Apple Computers Mac OS X 10.5 operating system upgrade, code-named Leopard, will feature a new application performance measuring tool named Xray, new security enhancements and a long-rumored resolution-independent user interface.
Apple disclosed these enhancements the week of Oct. 23 on its new Web page, “Leopard Technology Series for Developers.”
Xray, according to Apples site, will allow developers to “track UI events in real-time and see how they affect I/O activity and CPU load at the same time.”
This application will be based on the open-source DTrace, but provide a graphical interface to that utilitys command-line monitoring of kernel and user code.
“Xray is an important new development tool, and given its ability to add virtualization and real-time tracking of the UI development process, it should make developing software for the Mac an easier and more responsive experience,” said Tim Bajarin, a principal analyst at Creative Strategies of Campbell, Calif.
At the other end of the spectrum—affecting users more than developers—is resolution independence. This will allow the operating system to present user interface elements at various scales.
This will decouple the physical image size from the pixel density of computer screens. The Mac OS has historically assumed 72 dots per inch, but new displays can go over 100 dots per inch.
As a result, users will be able to have the same size interface, but with more pixels per inch. Alternately, users with impaired vision will be able to scale up the physical size of the screen at a higher resolution.
In addition, the page mentions other technologies that are new to Leopard, such as improvements to Apples implementation of OpenGL, QuickTime upgrades and more details on how much 64-bit code will be in Leopard, even while maintaining 32-bit compatibility.
The page also outlines some technologies previously shown by Apple CEO Steve Jobs at this summers Worldwide Developers Conference. These include a new version of Xcode, Apples software development environment, and Dashcode, a development tool for Dashboard widgets.
“As a developer, whatever makes my programming life easier, Im for,” said Rich Siegel, CEO and president of Bedford, Mass.-based Bare Bones Software.
“Xray looks like its first-class,” Siegel said. “Its ability to analyze runtime behavior of an application dynamically should lead to better software products,” he added.
Siegel has used the performance tuning products currently provided by Apple, including Shark and other memory debuggers, but he said he could see an instant gain in using Xray.
He also pointed to code signing, a newly unveiled security feature, as being significant.
Code signing, Siegel said, is a two-step measure: First, it can verify that a piece of software was produced by the purported source, and second, that the code has not been subsequently altered.
“This means that when you run a piece of software with a digital signature,” he said, “you can trust it.”
“At the user level, there are some really interesting APIs,” Siegel said, pointing out Core Animation, a user interface animation feature that could enable developers to add advanced, real-time motion effects to their applications.
“These improvements to the operating system and developer tools affect everyone,” Siegel said.
“Leopard is, so far, a release for developers,” said Wil Shipley, CEO of Seattle, Wash.-based Delicious Monster, the maker of the cataloging utility Delicious Library.
“Apple has re-thought some of their core technologies, the ones that developers use every day, and made them simultaneously faster, easier to use, and more powerful,” he said.
“Specifically,” Shipley said, “Objective-C 2.0, with garbage collection, built-in enumeration, and automatic class property generation, is the only major revision to Objective-C since NeXT started using it in 1989.”
Garbage collection is an automated method of managing memory requirements of applications.
Without it, programmers have to manually allot system memory for their applications, then make sure manually that the application releases the memory once its no longer needed. Memory management errors can cause applications to crash.
“Its huge to developers both for the new features it offers but also because it signals a sea change for Apple: Objective-C is their language, and they can do with it as they please,” Shipley said.