App Service on Linux supports
.NET as a runtime stack built-in image.
.NET Update Policy - App Service upgrades the underlying .NET runtime and SDK of your application as part of the regular platform updates. As a result of this update, your application will be automatically updated to the latest patch version available in the platform for the configured minor version of your app. For more information about current supported node.js versions check Support Timeline.
Find additional .NET articles on Technet/TechCommunity - Apps on Azure Blog.
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