(from "About" article below. Security fixes listed in separate doc.)
"The OS X El Capitan v10.11.6 Update improves the stability, compatibility, and security of your Mac, and is recommended for all users.
Resolves an issue that may prevent settings from being saved in accounts with parental controls enabled.
Resolves an issue that prevented some network devices, such as speakers and multifunction printers, from accessing SMB share points.
Improves startup time when connecting to a NetBoot server.
Resolves an issue that may prevent startup from a NetBoot image created with an OS X v10.11.4 or OS X v10.11.5 installer.
Resolves an issue that may cause Active Directory authentication to take longer than expected."
(see below for doc on security fixes)
FYI: Not sure how common it is, but several posts on problems at Apple's El Capitan forums in a thread titled 10.11.6 update crippled my Mac Pro - replies not limited to Mac Pros. (Not all replies noted problems, although several did. One reply said reinstalling with Combo Updater helped. If you have any anti-virus software installed, it's recommended to remove/disable it before updating.)
FYI on Nvidia Driver Updates: Users of Nvidia's web drivers know that new OS X updates (versions or build numbers) require updated Nvidia graphics drivers. (Some non-Mac EFI cards are not supported by default OS X drivers.) They usually appear first in Nvidia's driver prefs update check. See July 19th/20th news page for Nvidia graphics driver updates for OS X builds after the above updates.
About Safari 9.1.2 Update:
See below for info on Safari 9.1.2 which is normally included with the latest OS X update (10.11.6), but only the doc about the security fixes in 10.11.6 mentions it at the bottom of the page "OS X El Capitan v10.11.6 includes the security content of Safari 9.1.2.". I'm not running El Capitan but some users say Safari 9.1.2 was not included in the 10.11.6 update from the Mac App Store. (See July 19th post There is no Safari update in the MAS, however a later post said the 10.11.6 COMBO updater (link above) did include Safari 9.1.2. May no longer be an issue by the time you read this.)
It should also be available via software update for Mavericks and Yosemite.
OS X Server v5.1.7 for OS X 10.11.6 (changes from app store page)
Profile Manager - Fixed an issue affecting Server installations configured with a third-party SSL certificate that prevented MDM enrollment using DEP
Apple Developer News notes Beta 3 of macOS Sierra, Xcode 8, iOS 10.0, tvOS 10.0, watchOS 3.0 available.
Freeware VM VirtualBox 5.1 "Major Update" (see Change Log for details)
Adobe Security Updates for Flash Player, Acrobat & Reader, XMP Toolkit for Java
Reviews of 4TB Samsung 850 EVO SSD
Doom Vulcan Patch released (and FAQ)
Apple Support/How-To Article Updates:
- About OS X Recovery
- How to reinstall OS X
- What to do before selling or giving away your Mac
- Using AirPlay to display video from your Mac on an HDTV
- Apple Thunderbolt cables and adapters (w/list of compatible macs)
- About iCloud Photo Library (Guide/How-To)
- About Family Sharing (Guide/How-To)
- Apple Web Server notifications