Replace Crystal Reports in Delphi by a service-based .NET implementation

The acronym REST stands for 'representational state transfer'. This software architecture is specially suited for HTTP-based interfaces. Within this framework, resources are selected by the URL, while data content is passed as JSON in the request or response body. The requested action follows from the HTTP verb, i.e. GET, POST, DELETE. Additional attributes may be appended as query parameters at the URL. The tool Crystal Report is particularly popular because it enables the definition of complex reports with a graphical design software. Switching to another report tool would have been disruptive and so is avoided, as extensive reworking is to be expected. Likewise, reprogramming of the Delphi application with .NET means can only be achieved at great expense of time and under possibly strong disruptive side effects.