1 Introduction

The HTTP (HyperText Transfer Protocol) is the W3C standard protocol for transferring information between a web-client (e.g., a browser) and a web-server. The protocol is a simple envelope protocol where standard name/value pairs in the header are used to split the stream into messages and communicate about the connection-status. Many languages have client and or server libraries to deal with the HTTP protocol, making it a suitable candidate for general purpose client-server applications.

In this document we describe a modular infra-structure to access web-servers from SWI-Prolog and turn Prolog into a web-server.

Acknowledgements

This work has been carried out under the following projects: GARP, MIA, IBROW, KITS and MultiMediaN The following people have pioneered parts of this library and contributed with bug-report and suggestions for improvements: Anjo Anjewierden, Bert Bredeweg, Wouter Jansweijer, Bob Wielinga, Jacco van Ossenbruggen, Michiel Hildebrandt, Matt Lilley and Keri Harris.

Path wildcarts (see http_handler/3) have been modelled after the‘arouter` package by Raivo Laanemets. Request rewriting has been added after discussion with Raivo Laanemets and Anne Ogborn on the SWI-Prolog mailinglist.