How do you tell the Visual Studio project type from an existing Visual Studio project

In the project XML files:

Console applications contain:

<OutputType>Exe</OutputType>

WinForms applications contain:

<OutputType>WinExe</OutputType>

Library (.dll) projects contain:

<OutputType>Library</OutputType>

and do NOT contain a

<ProjectTypeGuids>

ASP.NET and WCF projects contain:

<ProjectTypeGuids>{603c0e0b-db56-11dc-be95-000d561079b0};{349c5851-65df-11da-9384-00065b846f21};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}</ProjectTypeGuids>
<OutputType>Library</OutputType>

The GUIDs do something to define exactly what type of project it is. The ones above were taken from an ASP.NET app. They exist in WCF projects too, and flipping around the GUIDs can fool Vis Studio into changing the project type when you open it.

Some further research and I found this:

INFO: List of known project type Guids.

My .sln file contains:

Visual Studio 2005
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AddNumbers", "AddNumbers.csproj", "{2C81C5BB-E3B0-457E-BC02-73C76634CCD6}"

The link shows:

Project Type Description Project Type Guid
Windows (C#) {FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}

So it's Windows C# and the subtype is as per @HardCode's reply. In my case, it's "Console Application".

The .vproj file defines the project type, for example, the following defines a C++ project.

<VisualStudioProject
   ProjectType="Visual C++"

The project tag also includes the compiler version.