A popular convention for generic use. Commonly used by a main build script.

Examples:

build.proj

main.proj

company.product.build.proj

.targets files are those which is meant to be imported into other files using the Import element. Since these files are strictly re-useable they don’t actually build anything. They typically are missing the properties and item values to actually build anything.

Examples:

Microsoft.Common.targets

Microsoft.CSharp.targets

Microsoft.Data.Entity.targets

Language specific convention where **** represents the language short acronym.

Well-known extensions:

.csproj    | C#

.vbproj    | VB.NET

.vcxproj   | Visual C++

.dbproj    | Database project

.fsproj    | F#

.pyproj    | IronPython

.rbproj    | IronRuby

.wixproj   | Windows Installer XML (WiX)

.vdproj    | Visual Studio Deployment Project

.isproj    | InstallShield

.pssproj   | PowerShell

.modelproj | Modeling project

A project property sheet used by Visual C++ projects (.vcxproj).

Examples:

Microsoft.Cl.Common.props

Microsoft.Cpp.CoreWin.props

Microsoft.Cpp.props

Microsoft.Link.Common.props

A common include file to be imported by a calling MSBuild project. Contains a list of <UsingTask> elements.

Examples:

Microsoft.Common.Tasks

MSBuild.ExtensionPack.tasks

(This is a related convention if not strictly-speaking a file extension.)

A common include file to be imported by a calling MSBuild project. Contains “various properties related to shared utilities used during the build and deployment processes as well as any other common settings” (Sayed Ibrahim Hashimi, 2009).

Examples:

EntityFramework.settings.targets

Compiler.settings.targets

Library.Settings.targets