Object efforts gravitate - Microsoft's OLE architecture and the Object Management Group's Common Object Request Broker Architecture - Technology Information

Software Magazine, March, 1996 by George Lawton

Microsoft's OLE and the OMG's Corba are orbiting toward interoperability, as users wait for distributed object standards to touch down

IS managers everywhere have a dream: an open, distributed object infrastructure that would enable them to create applications out of pre-assembled components, and distribute these across the network. They would not have to worry about porting their application to other platforms. In fact, they would not even have to worry about where the application would run.

The industry is still years away from this level of technology. However, standards are beginning to emerge that could turn this dream into reality. The two predominant efforts include Microsoft in the PC desktop arena, with the OLE architecture, and the Object Management Group (OMG) in the Unix arena, with the Common Object Request Broker Architecture (Corba). Meanwhile, IBM and Apple are trying to position OpenDoc as a cross-platform object framework. And the growing popularity of Sun Microsystems' Java programming language may impact the standards arena.

While Microsoft did not design OLE to be object-oriented, the technology has the ability to create "component-ware" that can be plugged into other software. Also, applications created from different vendors can share data using OLE as an interface.

In the past, OLE was limited to running on standalone IBM-compatible PCs, but that's quickly changing. Microsoft has ported OLE to the Macintosh, and Microsoft partners are porting versions of OLE to other platforms, ranging from the AS/400 to mainframes. Microsoft is also getting ready to release a distributed OLE capability later this year. This will enable applications on the desktop to communicate directly with OLE applications on other PCs, midrange systems or even mainframes.

The OMG's Corba is a platform- and vendor-independent architecture for creating object-oriented applications that can communicate with each other over networks. Version 2.0 of Corba has been released, and vendors have started shipping products based on it.

The current version of Corba enables objects to send messages to each other. However, it does not address a number of important issues required for implementing mission-critical applications, such as fault tolerance.

Specifications for other services, such as transaction processing and concurrency, have been established, but they have not made it into any commercial products yet.

As for OpenDoc, it has suffered constant delays in its introduction. However, the first versions for OS/2 and the Macintosh have started shipping, and IBM claims Windows and AIX versions are just around the corner.

To encourage use of the technology, Apple has brought the standard to the OMG as the Common Facility RFP 1, which was still awaiting approval as of this writing.

If IS managers can rapidly create new applications using existing technology, why should they care if there's an object standard? Because standards will bring competition to the object marketplace. Standards will also enable plug-and-play interchange between different applications and components.

Bob Hodges, member of the technical staff at Texas Instruments, Plano, Texas, said object standards are very important to TI's future software development.

His company is closely tracking the development of Corba and OLE. "We need to be able to deliver software solutions more quickly than we have in the past," said Hodges. "Standards will be important to achieve cycle times because they will allow us to plug together solutions from predefined parts."

Although Microsoft is not in the standards business, Windows software dominates the desktop PC market. One of the great advances of Windows has been the ability to integrate multiple applications on the desktop. For example, MapInfo Corp., Troy, N.Y., has developed an extensive library of mapping software for the PC envi-ronment. Using OLE, users can work with maps in their word processor or spreadsheet, for instance.

"It is clear that OLE has been accepted as a good technology for the integration of applications on the development side and the user side," said Steve Lawler, software development manager at MapInfo. "I think it is becoming an important part of how to integrate applications with each other so there is less of a vertical breakup [between applications] on your desktop."

"There are two faces of OLE," said Jeff Alger, senior product manager, developer division at Microsoft. "The side that has been the most visible is the compound document. The other side of OLE has been its use as a system object model, independent of the user interface. What we are working on now, in the form of networked OLE, is completing the implementation of that architecture as opposed to introducing a new architecture.

"That functionality to distribute components across the net is done without changing the APIs," he continued. "It does introduce some new ones for security. The fundamental programming model is the same as what is used today. Code written to OLE 2.0 that is 32-bit will be able to take advantage of OLE's distributed features." According to Alger, networked OLE is scheduled to ship in Q2/96 with the Shell Update Release of Windows NT, better known as NT 4.0.