The web service technology from .NET 1.0, now considered a "legacy technology".
The web service technology from .NET 1.0, currently considered a "legacy technology". For new development of web services or web service clients the use of Windows Communication Framework (WCF), ASP.Net Web API or other modern frameworks is recommended.
The ASMX Web Service technology was introduced with .NET 1.0 as "ASP.NET Web Services", and has also been called "XML Web Services". The term "ASMX" refers to the file type of the web service endpoints, such as WebService1.asmx. Note what Microsoft says about their ASMX Forum:
This forum has been retired. It is locked, but is still available for review in the Archived Forums folder. Any future posts on this topic should be put in the Windows Communication Foundation, Serialization, and Networking forum.
ASMX Web Services only support SOAP or JSON over HTTP or HTTPS, and have limited extensibility.
Important ASMX Questions
- VS2003 Web Reference for a WCF Service has Extra "IdSpecified" Parameter (or if your integer or other primitive type parameters disappear)
- Difference between web reference and service reference?
Other Obsolete Technologies
Web Service Extensions, or WSE were a set of stopgap releases that added to the ASMX technology to permit developers to work with the emerging WS-* standards as they were being developed by the industry. That means you will often find WSE mentioned in conjunction with security. This does not mean that WSE is the solution to security in web services, it means that WSE was that solution until WCF was released. WCF supersedes WSE, which is now obsolete. In fact, WSE is not supported on Windows 2008 or later releases, and is not supported by Visual Studio 2008.
Even more obsolete is the SOAP Toolkit. This was a way to create clients for web services, and worked for old VB or ASP applications. Do not use it.