Apple yesterday updated OS X El Capitan, patching a slew of security vulnerabilities, fixing other non-security bugs, and adding capabilities to some first-party apps.
The Cupertino, Calif. company also issued less sweeping updates -- composed only of vulnerability fixes -- to OS X Yosemite and OS X Mavericks, the 2014 and 2013 editions, respectively.
OS X 10.11.4, the fourth update to El Capitan since its September debut, addressed 56 vulnerabilities. Twenty-three applied to OS X Yosemite and 22 to Mavericks.
Apple stopped patching Mavericks' predecessor, 2012's OS X Mountain Lion last year, as part of its practice to support only the OS X editions designated as "n," "n-1" and "n-2," where "n" is the newest. Under that scheme, El Capitan is "n," Yosemite is "n-1" and Mavericks is "n-2." As "n-3," Mountain Lion has been retired.
The three newest versions of OS X powered 88% of all Macs that went online in February, according to Web analytics vendor Net Applications. Likewise, 12% of all Macs worldwide ran a retired operating system that, while it continues to work, no longer receives security updates.
OS X 10.11.4 also featured non-security improvements in stability and compatibility -- Apple limits those changes to the latest edition -- that ranged from importing of Evernote files into Apple's own Notes application, to a new ability for sharing Live Photos between iOS and OS X via AirDrop and Messages.
Live Photos -- a feature restricted to the iPhone 6S and 6S Plus -- creates semi-animated photographs by capturing 1.5 seconds of audio and video both before and after the shutter button is pressed.
Computerworld tested the Live Photos support using Messages, and it worked as advertised.
Other El Capitan modifications fixed compatibility problems between the operating system and Cisco's widely used-in-the-enterprise AnyConnect VPN client, and improved the reliability of connecting a Mac to the Internet using the iPhone's Personal Hotspot tool.
OS X 10.11.4 can be downloaded from the Mac App Store; an El Capitan-powered Mac owner can retrieve the update by selecting "App Store" from the Apple menu, then clicking on the "Updates" icon at the top right of the store's window.
The patch-only update for Yosemite and Mavericks -- dubbed Security Update 2016-002 -- can also be downloaded from the Mac App Store's Updates section to systems running those editions.