问题
We're considering writing the next version of out project in using .Net 3, but are wondering if we can take the hit on forcing end users to install the .net framework version 3.
回答1:
If you want to ensure you are only using .NET 2.0 compatible functionality then you should only use .NET 2.0 assemblies. Then you know your safe and sound.
回答2:
This article from Jean-Baptiste Evain explains how you can use C# 3.0 and LINQ and targeting machines on which there is only .NET 2.0 runtime installed.
The idea is to use System.Core Mono implementation, which is licensed under the MIT/X11 license.
回答3:
.NET 3.0 is a bad name for some new libraries: WPF, WCF, Workflow and InfoCard. The CLR is still version 2.0, ASP.NET is still version 2.0, and Windows Forms is still version 2.0.
In development, .NET 3.0 was called WinFX.
来源：https://stackoverflow.com/questions/138393/can-you-run-a-version-3-net-binary-on-a-version-2-clr-install