.ASMX File Extension

Defines Web services called by an Active Server Page (.ASP file); automatically compiled by ASP.NET when a request to the service is made; can be accessed over the Internet or from a local network.

ASMX files begin with the ASP.NET directive "WebService," followed by the "Language" parameter. This is used to set the programming language to Visual Basic, C#, or JScript. They can be run using a Windows-based Web server with the .NET framework.