Your 4D application can publish Web services in either DOC or RPC style, with just a single click. In addition, you get programmatically controllable security features and automatic WSDL (Web Services Definition Language) publication.
The 4D Web Services Expansion allows you to publish unlimited Web services from your 4D application. It can be linked either to 4D Server or to the client-side application (i.e the 4D Client license). This allows you to launch your Web Services from a distinct machine, typically in a DMZ, or to execute a number of different Web services linked to the same database. However, you must choose your option when you purchase your Web Services Expansion as activating the feature is not the same between 4D Server and 4D Client.
This expansion is included with 4D Developer Professional and 4D Team Developer Professional for development and testing purposes.