Apple’s operating system developers are hard at work pushing to get out the next major version of the Mac OS X Snow Leopard. In addition to delivering a new test build of the upcoming Mac OS X 10.6, Apple introduced a new build of the next incremental update to the current “Leopard” version of Mac OS, which will be 10.5.7. The current Mac OS X 10.5 family release is Mac OS X 10.5.6, which was released in December 2008. Apple released build 10A335 of Snow Leopard to developers on April 23. This build comes just three weeks after the previous test release. Apple also released Build 9J56 of Mac OS 10.5.7, which features “Bluetooth compatibility and stability fixes,” according to one report.