The pre-release software, labeled Mac OS X 10.6.3 build 10D561, arrives exactly two weeks after the Mac maker equipped developers with build 10D552, which similarly listed no known issues.
People familiar with the latest beta claim no changes have been made to the software's enhancements checklist, which includes an update to QuickTime X that improves security and compatibility while simultaneously enhancing overall reliability.
Other changes present since earlier betas include tweaks that enhance the performance of Apple's 64-bit Logic pro audio suite and improved compatibility with third-party printers and OpenGL-grounded applications.
Those familiar with Wednesday's beta say Apple is now asking developers to focus their evaluation efforts on Bluetooth, iChat, and USB, in addition to two previously listed focus areas: graphics drivers and QuickTime.
An earlier emphasis on AirPort testing has reportedly been omitted from build 10D561.
Mac OS X 10.6.3 currently weighs in at just over 716MB in Delta form, down slightly from the 737MB package distributed with the previous seeding.