Add macOS 11 onboarding guide

README.md

@@ -17,14 +17,12 @@ For general questions about using the virtual environments or writing your Actio
 | Windows Server 2019 | `windows-latest` or `windows-2019` | [windows-2019] | [![](https://actionvirtualenvironmentsstatus.azurewebsites.net/api/status?imageName=windows-2019&badge=1)](https://actionvirtualenvironmentsstatus.azurewebsites.net/api/status?imageName=windows-2019&redirect=1)
 | Windows Server 2016 | `windows-2016` | [windows-2016] | [![](https://actionvirtualenvironmentsstatus.azurewebsites.net/api/status?imageName=windows-2016&badge=1)](https://actionvirtualenvironmentsstatus.azurewebsites.net/api/status?imageName=windows-2016&redirect=1)
 ```
-The macOS 11 virtual environment is currently provided as a private preview only.
-The "macos-latest" YAML workflow label still uses the macOS 10.15 virtual environment.
+Ubuntu 16.04 has been deprecated and will be removed on September 20, 2021.
+Existing workflows using `Ubuntu 16.04` should migrate to `Ubuntu 20.04` or `Ubuntu 18.04`
 ```
 
-```
-Ubuntu 16.04 is being deprecated. It is not recommended for new users. 
-If any of your workflows use Ubuntu 16.04, migrate to Ubuntu 20.04 or 18.04.
-```
+> The macOS 11 virtual environment is currently in preview, and is automatically available to existing Enterprise plan customers. New Enterprise plan customers, or customers on other plans, should fill the form to request access to macOS 11 virtual environment. Please view our [Big Sur guide](./docs/macos-11-onboarding.md) for more details. <br/>
+The `macos-latest` YAML workflow label still uses the macOS 10.15 virtual environment.
 
 ***What images are available for GitHub Actions and Azure DevOps?***
 The availability of images for GitHub Actions and Azure DevOps is different. See documentation for more details:  
@@ -62,4 +60,4 @@ You can also track upcoming changes using the [awaiting-deployment](https://gith
 [self-hosted runners]: https://help.github.com/en/actions/hosting-your-own-runners
 
 ## Software and image guidelines
-To learn more about tools and images support policy, see the [guidelines](./docs/software-and-images-guidelines.md).
+To learn more about tools and images support policy, see the [guidelines](./docs/software-and-images-guidelines.md).

docs/macos-11-onboarding.md

@@ -0,0 +1,25 @@
+# macOS 11 (Big Sur) onboarding guide
+
+macOS 11 pools were opened to existing customers only, and we are working on making them ready for production use, rebalancing capacity, and analyzing possible load.
+
+Meanwhile, we'd like to start including customers to private preview on demand. 
+
+> Big Sur will automatically become available to existing Enterprise customers. New enterprises and customers on other plans, please go through the sign up process described below.
+
+## Sign up process
+
+If you need to build and test your project with macOS 11, please, fill out the [form](https://forms.office.com/r/Pn0a7NqBXg).
+
+We will review the incoming requests periodically and open macOS 11 pool for some amount of them. These are the aspects we consider when processing requests:
+- _Pool capacity_. New onboardings are only possible if current performance won't degrade for existing customers.
+- _Billing plan_. New Enterprise or Teams customers will be given a priority in joining macOS 11.
+- _Necessity of macOS 11_. We can currently afford to add only those projects that really depend on the latest macOS version and its features.
+
+## Usage
+
+macOS 11 image label was changed to `macos-11` to avoid confusion with the minor version. We always update images to the latest available OS version. Use the following code snippet to run your builds on macOS Big Sur:
+```
+jobs:
+  build:
+    runs-on: macos-11
+```