"About AirPort Base Station Firmware Update 7.8 Information
Firmware update 7.8 adds AirPlay 2 support to 802.11n AirPort Express base stations."

"macOS 10.13.6 Supplemental Update 2 for MacBook Pro (2018) (1.3 GB)
The macOS High Sierra 10.13.6 Supplemental Update 2 improves the stability and reliability of MacBook Pro with Touch Bar (2018) computers, and is recommended for all users."

(My earlier comment follows, before Apple posted the update download page.)
I saw Apple's Developer releases list new macOS 10.13.6 Builds 17G2307 & 15P6805, so assumed another update for 2018 MBPs. (The late July Supplemental update for 2018 MacBook Pros was posted shortly after the Developer page listed 10.13.6 builds 17G2208/15P6703. Although not mentioned on the download page, thought to be an attempt to fix throttling issues with some 8th gen Core CPUs.)

• Apple Announces New iPhone Event as Handset, Watch Images Leaked (bloomberg)
  
  
• Blackmagic external GPU review: A very Apple graphics solution (ars)
  (Apple's use an external graphics processor with a Mac lists several eGPU kits, including link to using Blackmagic eGPU with your Mac. Its GPU isn't upgradeable.)
  
  
• Safari Technology Preview 64 release notes (for macOS High Sierra & Mojave beta)
  
  
• Intel Launches Whiskey Lake-U & Amber Lake-Y: New MacBook CPUs? (anandtech)
  
  
• Report: Apple Mac Weakness exploited In Middle East Espionage (forbes)
  
  
• Apple Buys Augmented-Reality Display Startup Akonia Holographics (bloomberg)
  
  
• Micromat Machine Profile v1.3.2 update (use in-app update check*)
  (* If running OS X 10.6.x, don't update. v1.3.1 & newer require OS X 10.7 or later.)
  - Fixed missing Intel Core i9 processor model
  - Updated machine and location identification strings
  - Other minor fixes and enhancements
  
  
• Security update for Adobe Creative Cloud Desktop Application (adobe)
  
  
• Mac Pixelmator 3.7.4 (OS X Yosemite or later. Pro version requires 10.13 or later)
  - Fixed several different memory leak issues.
  - On some Mac computers, it was not possible to edit text layers. Fixed.
  - Improved stability when its internal preference files are manually removed.
  - Rarely Pixelmator would quit unexpectedly when loading the Fonts window. Fixed.
  - A range of stability improvements to the Quick Selection, Color Selection, Paint Bucket, Magic Eraser, and painting tools, as well as the Pixelmator undo system.
  
  
• Apple to Embrace iPhone X Design With New Colors, Bigger Screens (bloomberg)
  
  
• '[GAME] is not optimized for your Mac' alert. (aspyr support)
  (updated again Aug. 27th/28th. Regarding 32-bit games and macOS Support.)

• Apple Vintage and obsolete products list
  
  
• How to Update the firmware on your AirPort base station
  
  
• AirPlay system requirements (includes AirPlay 2 and compatible devices/speakers)
  - Article updated to add Airport Express 802.11N with v7.8 firmware update.
  
  
• How to Transfer content from a previous iOS device to a new iPhone, iPad, or iPod touch
  
  
• How to set a firmware password on your Mac
  
  
• About the security content of macOS High Sierra 10.13.6 Supplemental Update 2 for MacBook Pro (2018) (simply says it includes the security content of macOS 10.13.6 release.)
  
  
• If your Mac won't turn on
  
  
• How to Locate backups of your iPhone, iPad, and iPod touch

Page of How-To, Troubleshooting & Tips for Mac/OS X/iOS Users from Airplay to Thunderbolt.