In terms of the extensions it added to COM, DCOM had to solve the problems of
One of the key factors in solving these problems is the use of DCE/RPC as the underlying RPC mechanism behind DCOM. DCE/RPC has strictly defined rules regarding marshalling and who is responsible for freeing memory.
DCOM was a major competitor to CORBA. Proponents of both of these technologies saw them as one day becoming the model for code and service-reuse over the Internet. However, the difficulties involved in getting either of these technologies to work over Internet firewalls, and on unknown and insecure machines, meant that normal HTTP requests in combination with web browsers won out over both of them. Microsoft, at one point, attempted and failed to head this off by adding an extra http transport to DCE/RPC called ncacn_http (Network Computing Architecture, Connection-based, over HTTP). This was later resurrected to support an Exchange 2003 connection over HTTP.
The Wine Team is also implementing DCOM for binary interoperability purposes; they are not currently interested in the networking side of DCOM, which is provided by MSRPC. They are restricted to implementing NDR (Network Data Representation) through Microsoft's API, but are committed to making it as compatible as possible with MSRPC.
J-Integra for COM is a mature commercial pure Java implementation of the DCOM wire protocol allowing access to COM components from Java clients, and Java objects from COM clients.
To access DCOM settings on a computer running Windows 2000, Windows XP and earlier, click Start > Run, and type "dcomcnfg". (Click NO for any warning screens that appear.)
This opens the Distributed COM Configuration Properties dialog.