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.