Robert 的部落格

[Visual Studio 2012]

*.sln

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 2012

*. csproj

<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

或

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

[Visual Studio 2010]
*.sln

Microsoft Visual Studio Solution File, Format Version 11.00
# Visual Studio 2010

[Visual Studio 2008]
*.sln

Microsoft Visual Studio Solution File, Format Version 10.00
# Visual Studio 2008

*. csproj

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

參考資料：
open visual studio 2012 projects in visual studio 2008
C# 2008開啟 C# 2013建立之方案/專案
[VS] VB2008 與 VB2012 共同編輯原始碼