macOS

Founders & Origins

• Apple Inc. was founded in 1976 by Steve Jobs, Steve Wozniak, and Ronald Wayne.
• The first Macintosh computer was released in 1984, running the Classic Mac OS.
• In 2001, Apple introduced Mac OS X, a Unix‑based successor to Classic Mac OS.
• In 2016, the name was changed to macOS to align with iOS, watchOS, and tvOS.

Historical Evolution

• Classic Mac OS (1984–2001): Early GUI system, single‑tasking, limited memory protection.
• Mac OS X (2001): Unix foundation, Aqua interface, improved stability.
• macOS (2016–present): Modernized design, tight ecosystem integration, optimized for Apple Silicon.
• Latest versions: macOS Ventura (2022), Sonoma (2023), Sequoia (2024), Tahoe (2025).

Architecture

• Kernel:
  • XNU (X is Not Unix): Hybrid kernel combining Mach microkernel and BSD components.
  • Provides multitasking, memory management, and hardware abstraction.
• File System:
  • APFS (Apple File System): Introduced in 2017, optimized for SSDs, supports snapshots and encryption.
• User Interface:
  • Aqua GUI: Dock, Finder, Spotlight, Mission Control.
• Security:
  • Gatekeeper, System Integrity Protection (SIP), sandboxing, frequent updates.

Key Features

• Seamless Ecosystem: Works with iPhone, iPad, Apple Watch (AirDrop, Handoff, Universal Clipboard).
• Built‑in Apps: Safari, Mail, iMovie, GarageBand, Pages, Numbers, Keynote.
• Developer Tools: Xcode, Terminal with Unix commands.
• Performance: Optimized for Apple Silicon (ARM64), still supports Intel x86‑64.