Mac OS X 10.1 (code named Puma) is the second major release of macOS, Apple's desktop and server operating system.

The operating system was handed out for free by Apple employees after Steve Jobs' keynote speech at the Seybold publishing conference in San Francisco.

It was subsequently distributed to Mac users on October 25, 2001, at Apple Stores and other retail stores that carried Apple products.

Mac OS X 10.1 was codenamed "Puma" because the internal team thought it was "one fast cat.

Hard Drive Space: Apple introduced many features that were missing from the previous version, as well as improving overall system performance.