Microsoft COM Component Object Model Microsoft Corporation ™

What is COM? Build software from parts, not from scratch  A framework for creating and using components  Makes software easier to write and reuse  Provides widest choice in services, tools, languages, and applications  Provides the only currently viable third party market for off the shelf components ($410 M excluding MSFT Source: Giga)  Controls, tools, and server components

COM Features  Services used in a standard way, regardless of location  Any Programming Language  Integrated with Development Tools  Flexible Security  Multiple Network Transports  Mature specification and reference implementation  Ubiquitous

Accessing COM Services Client Component In the same process Fast, direct function calls Client Component COM Client Process Server Process On the same machine Fast, secure IPC Across machines Secure, reliable and flexible DCE-RPC based DCOM protocol COM DCE RPC Client Server Machine Client Machine COM Component

Major COM services Shipping now:  Security  Lifecycle management  Type information  Monikers (Naming)  Database access  Data Transfer  Components  Transactions  Asynchronous communications  Registry  Automation (Dynamic Invocation) Shipping soon:  Directory (NT 5.0)

Windows Platform General purpose Web professional Component developer Commercial professional developer Borland Delphi Delphi AdobePageMaker MacromediaDirector PowerSoft PowerBuilder NetObjects Fusion SoftQuad HotMetal Pro Borland Intrabuilder Intrabuilder PowerSoft NetImpact Borland Latte Latte Any Language/Tool

COM: Multiple Network Transports TCP, UDP IPX, SPX HTTP Server Machine Client Machine COMCOM Queued Clients COMCOM COMObject

COM: Flexible Security TCP, UDP IPX, SPX HTTP Server Machine Client Machine COMCOM Falcon Clients NT4 Security SSL/Certificates Kerberos IPSEC COMCOM COMObject

COM Client Linux 2.0 (Intel) BETA COM HP/UX COM Digital Open VMS COM Siemens Nixdorf SINIX COM SCO UnixWare COM Digital Unix 4.0 (Alpha) RC COM IBM MVS (OS390) COM IBM OS/400 COM IBM AIX COM DCOM Sun Solaris (Sparc) 2.5 RC COM Q3’97 Q1’98 H1’98 Q4’97 H1’98 Q4’97 COM: Ubiquitous Download the betas from

Driving trends  Growth in off the shelf component marketplace  Ubiquitous Win95 and NT  Commodity software  Cross platform adoption of COM  Richer, integrated software services  Growth of NT relative to UNIX

Scorecard

CORBA and IIOP fall short PC Week for June 30, 1997 by Michael Moeller “I would not recommend using IIOP [Internet Inter-ORB Protocol] for communications between a client and a server over the Internet, ” said John Dawes, group product manager at Netscape. August 1997 Byte Magazine Cover Story “The OMG’s effort to define interoperability began well before the current obsession with the Internet. As a result, it’s CORBA 2 architecture looks slightly old- fashioned, although classic would be a kinder word.”

COM Wins ORB Shootout 7/14/97 "We found that Microsoft has taken the bull by the horns to produce an extremely effective and practical distributed object technology implementation." "DCOM has the jump on CORBA in terms of its flexible security implementation. With CORBA, the security specification has only recently been completed. This has left ORB vendors to come up with their own incompatible security implementations."

Summary  What is COM all about  COM features  How the technical elements stack up  COM, CORBA, IIOP and ORBs

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