Microsoft Edge extensions: If you're a fan of Chrome extensions, then you'll be glad to hear that they're heading to Microsoft's Edge browser. The Anniversary Update brings support for extensions, and it's now up to third-party developers to fill the Windows Store with their add-ons.
Cortana improvements: Microsoft's digital assistant, Cortana, debuted on Windows 10 last year, and the software maker is bringing it to the lock screen with the Anniversary Update. You'll be able to ask it to make a note, play music, set a reminder, and lots more without ever logging in. Cortana is also getting a little more intelligent, with the ability to schedule appointments in Outlook or options to send friends a document you were working on a week ago.
Dark theme and UI tweaks: You can switch on what I call even darker mode in settings, and it will switch built-in apps that typically use a white background over to black.Other improvements include things like Windows 10's ability to set your time zone automatically, and opening up of Windows Hello, the biometric feature to apps and websites. Additionally, the Xbox One is getting Windows apps. The Verge adds, "It feels like a promise that was made years ago, but it's finally coming true with the Anniversary Update. As Windows 10 now powers the Xbox One, Microsoft will start rolling out an update to its console to provide support for Cortana on Xbox One and the new universal apps." Microsoft is also adding Bash, the Linux command line to Windows with the new update. It's an optional feature and users will need to enable it to use it. Users will also be able to "project to PC," a feature that will allow one to easily find a PC to project to from a phone or another PC. There's also a new Skype app, and syncing of notifications between PC and phone is getting better.
Going by the reviews, it appears Windows 10 Anniversary Update is substantially more stable, and has interesting new features. You can read the first impressions of it on ZDNet, and review on PCWorld.