Snow Leopard Reaches Gold Master Development

Mac OS X 10.6 Snow Leopard was completed in 2009 with an unusual goal for a major operating-system release: Apple emphasized internal engineering improvements more than visible features.

Snow Leopard moved more system components to 64-bit code, introduced Grand Central Dispatch for scheduling work across multiple CPU cores, and added OpenCL so applications could use GPUs for general computation. Apple also removed large amounts of PowerPC-era code and made system installation smaller.

The release reflected the hardware transition of the previous few years. Macs were now entirely Intel-based and increasingly multi-core, so the operating system could optimize around a cleaner architecture. Snow Leopard became well regarded because it showed that a platform release can be valuable even when the feature list is short: performance, memory use, concurrency, and developer APIs can matter more than a redesigned interface.