While many had expected Apple to follow last year's pattern and release a developer preview of OS X 10.9 early this year ahead of a summer public launch, the company has so far remained essentially silent about its plans for its next-generation Mac operating system. That silence does not, however, mean that Apple has not been working hard on the project since it first started showing up in web logs last fall. As spotted by an AppleInsider reader, circumstantial evidence of Apple's work showed up in a WebKit bug report early last month revealing that version of OS X 10.9 in testing was Build 13A451. According to Apple's build number scheme, "13" refers to OS X 10.9, "A" refers to the 10.9.0
