Appendix: COM/CORBA Integration

Summary

In 1995, the OMG published a COM/CORBA Interworking Request for Propsals (RFP). The RFP was composed of two parts. Part A dealt with interworking between CORBA and the commercially available implementation of COM. Part B dealt with interworking between CORBA and DCOM, which was still in development at that time. The OMG ratified Part A of the COM/CORBA Interworking Specification in 1996 and Part B in 1998. There are currently commercial implementations of Part A.

Our goal in this appendix is take a look at the concepts and considerations put forth in the specification. To begin, we will consider motivations for COM/CORBA integration. Then, we will give a very brief overview of COM. Moving into the meat of our topic, we will discuss a conceptual model for bridging, examine features common to COM and CORBA, and investigate mapping issues. We will look at locating and managing distributed objects from the perspectives of both COM and CORBA. We will conclude by examining COM/CORBA distribution issues.

From Whence We COM

COM evolved from OLE, Object Linking and Embedding, a technology which was developed for the single-user, single-machine environment of Windows 3.1. OLE enabled users to create and manage compound documents, thereby maximizing code reuse within and across applications on the Windows platform. OLE2 was designed to extend the paradigm to the component level. OLE2 interfaces and protocols mediate dynamic component interaction on a desk top.