4. Conclusion

The first part of this article provides an overview of the issues and key concepts involved in component-based programming, and explains why the move to components is crucial to building complex distributed applications for business. Secondly, we review the main industrial technologies (Java Beans, EJB, CCM, Microsoft) based on components. For each of them, we focused on their original points: event-driven communication and graphical assembly with Java Beans, description of system properties (transactions, persistence and security) and component host servers with Enterprise Java Beans, the new OMG IDL and deployment of OMG component packages, and Microsoft's global vision through its various technologies (COM, DCOM, COM+, MTS, MSMQ and ASP). Finally, we presented the OLAN project, illustrating the use of architecture description languages (ADL) to build distributed component-based applications....