The Internet and Web systems in particular have prompted a burgeoning development in software paradigms. Foremost among these is Extensible Markup Language (XML). While XML delivers a number of advantages, it is its use as a message exchange format that is both programming language and operating system platform independent that is relevant to this paper. The authors describe a development environment for building Web services in the C and C++ programming languages, based on the simple object access protocol (SOAP) and XML paradigms.

Web services require that information and requests for information be passed around the Internet in a consistent, open, standard form. SOAP is one such framework, which incorporates rules for defining the embedded datatypes, descriptions of the remote procedure calls/responses interfaces, and an envelope that encapsulates all of this material. This paper assumes an implementation of this protocol, known as gSOAP, and presents an introduction to the main features of gSOAP. These include the ability to map between SOAP/XML and their corresponding C/C++ data types and procedure/method calls; access to a range of embedded protocols, such as Hypertext Transfer Protocol (HTTP) and Secure Sockets Layer (SSL); a lightweight memory footprint; and real-time system compatibility, all in a platform independent way.

The primary thrust of the paper is to explain the use of gSOAP within the context of developing Web services. The principle is that developers can write much of their code in traditional C and C++ forms, and have gSOAP handle all the interfacing to the SOAP layer. The system will map a specification of the Web-services layer into C and C++ interfaces that perform all the assembly and disassembly of data and call interfaces between the programming level and the XML transport level. Thus, the programmer is free to concentrate on the functionality of the system, and the tedium of interfacing to the XML level is handled automatically. This is the main contribution of the paper.

There are several examples used to explain this principle, with diagrams and code fragments used reasonably appropriately. The reader would need to have some familiarity with the application of C and C++ in this environment to gain the most from the paper, since much of the discussion is perforce condensed. The paper concludes with a brief discussion of performance, which demonstrates that the system scales well with increasing message load, distributed over up to four concurrent clients and one server. No indication of its behavior under larger configurations is presented, however.