“Apple this week began testing Mac OS X 10.5.6, the next in a running series of updates planned for the Mac OS X 10.5 Leopard operating system, which could prove to be the most extensive yet,” Slash Lane reports for AppleInsider.

“The first test build, which reportedly arrive Thursday, is said to contain a sprawling laundry list of system components in need of evaluation. This list, which totals nearly six dozen, names almost every major component,” Lane reports.

“In its bare delta form, Mac OS X 10.5.6 is said to weigh in just shy of 350MB,” Lane reports. “Last week, Apple stepped up its testing efforts behind Mac OS X 10.6 Snow Leopard, providing a handful of its partners with a glimpse at new builds featuring a Finder completely re-written in Cocoa, the beginnings of Microsoft Exchange integration, and a new ImageBoot function.”

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