Supporting Multiple Versions of Visual Studio
The term side-by-side means that you can install and maintain multiple versions of a product on the same computer. For VSPackages, that means a user can have several Visual Studio versions installed on the same computer. However, you cannot have side-by-side versions of your VSPackages loaded into a single version of Visual Studio.
Before you make your VSPackage able to be loaded into side-by-side versions of Visual Studio, consider the following:
You must determine which side-by-side implementation strategy you want to follow.
For more information, see Choosing Between Shared and Versioned VSPackages.
Your solution and project file formats must fit your implementation strategy.
For more information, see How to: Upgrade Project Systems and Registering File Name Extensions for Side-By-Side Deployments.
Your installer must handle your implementation strategy so that versioned components, and also components shared across all versions, are correctly installed and registered.
Installing a version of Visual Studio also installs a corresponding version of the .NET Framework. For example, installing Visual Studio 2010 and Visual Studio 2012 on the same computer also installs versions 4.0 and 4.5 of the .NET Framework, respectively.