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 * The latest Prism Library is `8.1`
 * Prism 8 support NET 5 and dotnet Framework. Prism 6.x and below only DotNet Framework 4.8 and below
 
+## Legacy Documentation
+- [Prism 5](https://www.microsoft.com/en-sg/download/details.aspx?id=42572)
+- Another nice [link](https://www.cnblogs.com/DoubleChen/p/3687305.html)
+
+## Migration Guides
+- [Prism 4.1 to 5](https://learn.microsoft.com/en-us/previous-versions/msp-n-p/ff921144(v=pandp.40))
+  - `Microsoft.Practices.Prism.ViewModel` namespace deprecated. Please use `Microsoft.Practices.Prism.Mvvm`
+  - The `BindableBase` class replaces the `NotificationObject` class.
+  - EventAggregator Namespace and API Changes. **NEW** `Prism.PubSubEvents` namespace
+  - Regions Namespace API Changes
+    - `UriQuery` class was replaced with the `NavigationParameters`
+  - Namespace changes
+  ```cs
+  using Microsoft.Practices.Prism.ViewModel;
+
+  // change to
+  using Microsoft.Practices.Prism.Mvvm;
+  using Microsoft.Practices.Prism.Mvvm.Desktop;
+  using Microsoft.Practices.Prism.ShareInterfaces;
+  ```
+
+- [Prism 5 to 6](https://github.com/PrismLibrary/Prism/wiki/Release-Notes---6.0.0)
+  - Breaking Changes
+    - Removed `Microsoft.Practices` from all namespaces
+  - Created new xmlns namespace `http://prismlibrary.com/`
+
+- [Prism 6 to 8](https://prismlibrary.com/docs/wpf/converting-from-6.html)
+  - Bootstrapper class need to move to Application class
+  - use `xmlns:prism="http://prismlibrary.com/"`
+
+- [Prism 7.1](https://brianlagunas.com/whats-new-prism-7-1/)
+  - **BIG** changes. [Release Notes](https://github.com/PrismLibrary/Prism/releases/tag/v7.1.0)
+  - No longer be shipping or supporting MEF for WPF
+  - New `Prism.IoC` namespace
+  - For `Prism.WPF`, introduced new `PrismApplication` base class. `Bootstrapper` class deprecated.
+
+- [Prism 7 to 8](https://prismlibrary.com/docs/wpf/converting-from-7.html)
+  - [Release Notes](https://github.com/PrismLibrary/Prism/releases/tag/v8.0.0.1909)
+  - AutoWireViewModel is now default to true `prism:ViewModelLocator.AutoWireViewModel="True"`
+  - Removed `ILoggerFacade`. Use `Prism.Plugin.Logging`
+
+## Online Tutorial
+- [Prism 6 Unity - VS2015](https://www.c-sharpcorner.com/article/getting-started-mvvm-pattern-using-prism-library-in-wpf/)
+
 ## Tutorials
 - [View-ViewModel](./view-viewmodel.md)
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