OS X El Capitan (version 10.11) is the twelfth major release of OS X, Apple Inc.'s desktop and server operating system for Macintosh computers. It is the successor to OS X Yosemite and focuses mainly on performance, stability and security. OS X El Capitan includes features to improve the security, performance, design and usability of OS X.
OS X El Capitan has a new security feature called System Integrity Protection (SIP, sometimes referred to as "rootless") that protects certain system processes, files and folders from being modified or tampered with by other processes even when executed by the root user or by a user with root privileges (sudo). Apple says that the root user can be a significant risk factor to the system's security, especially on systems with a single user account on which that user is also the administrator. System Integrity Protection is enabled by default, but can be disabled.
OS X El Capitan takes the sorts of things that experts have been doing with third-party apps and utilities for years on the Mac and builds them right into the OS. Spotlight is becoming more than just a simple file search box. Window management is becoming easier. Notes is more than just a raw text box. Most of it left me nonplussed because all of these things didn't feel new and different to me — I've been finding ways to fix all of those problems for years with third party apps and add-ons. But with El Capitan, Apple's made the learning curve you usually have to climb to become a "power user" much more gradual.
*this software is available on Mac only - 5.65 GB needed
