SCOUG OS/2 For You - May 1996

IBM in new push with OpenDoc

OpenDoc beats Microsoft's OLE

The Internet and JAVA are coming too

by Peter Skye

I spent the six hour drive north from Los Angeles wondering what I'd be learning about IBM's new push on OpenDoc and the future of OS/2.

The occasion was IBM's OpenDoc seminar in San Mateo, a San Francisco suburb, and IBM spent the entire day showing OpenDoc's capabilities while running on OS/2. Do not take this choice of operating systems for the presentation lightly - IBM is firmly committed to OS/2, and their slow marketing push is due to, as one IBMer put it that day, "a lack of OS/2 applications" which IBM is forcefully resolving. OpenDoc is a tool that should put a lot of quality software on the OS/2 table.

Let's back up twenty seconds. CORBA (Common Object Request Broker Architecture) is a specification developed by the Object Management Group, a consortium of manufacturers. OpenDoc is an architecture developed jointly by Apple, IBM and Novell which is CORBA compliant. SOM (System Object Model) is IBM's implementation of CORBA; SOM technology is found in the IBM VisualAge line of compilers.

We still have ten seconds to go. IBM's new VisualAge compilers (C++, COBOL, SmallTalk etc.) all follow the SOM/CORBA specification, which allows programs and subroutines written in different languages to all be put together into one program that can be used on any machine. No rewriting of code for a new platform; no agonizing over the selection of a language. Program in any language (or languages) you want, and the resulting "objects" all run together cohesively. They can talk to each other and run each other, no matter what the original source code languages were, because all comply with the SOM/CORBA specification.

What this means is that OpenDoc source code is hardware and operating system independent.

A developer using OpenDoc for all Windows (Win32) application development is guaranteed to be able to run the same program (recompiled, of course) on OS/2... and thus the program's users aren't "locked into" Windows. All software can be compiled to run on any operating system.

Microsoft loses OLE lock

What's more, SOM/CORBA includes total support for Microsoft's "OLE," so the resulting programs are also Windows compatible. And you get compatibility with Macintosh, AIX and other platforms as well. Just recompile the source code for whatever platform you want to run it on.

Note that OpenDoc's being OLE compatible is no small strategic point. OLE is expected to be widely available, and SOM/CORBA support for OLE will "water down" Microsoft's hold on the marketplace by allowing OLE-oriented programs to run on any operating system, not just Windows. Microsoft will lose some control over the marketplace because the same source code can be compiled to any platform.

Besides, OLE has a lot of technical drawbacks, which makes OpenDoc much more enticing. It can't do true objects (yes, well, sometimes you need an object), can't do multiple activations, doesn't have release-to-release binary compatibility, doesn't have security, doesn't have version control, doesn't have real-time inheritance, and can't handle irregularly shaped components. Once the code writers are using OpenDoc for OLE support, the hope is that they'll discover and use the other OpenDoc features for which there is no OLE equivalent.

An OpenDoc part may be packaged in a binary class library and shipped as a DLL. Or, it may be dynamically loaded off the Internet or any other network.

IBM adds JAVA

And coming soon - SOM will have full support for all Internet JAVA applets.

Thus, instead of a program loading a DLL, which may not be the most current version, that same program can instead load a JAVA applet off the Internet. Some software developers may charge per-use applet fees (such as 10 cents per use), which for seldom used programs and advanced program features is much cheaper than buying the applicable software package. Users may also want to switch to using JAVA applets to make sure they always are running the most recent version (with the most recent bug fixes) of the software they're licensed for, especially when the user may be working on different machines (perhaps even different types of machines) at different times.

Java support will be released with SOM 3.0, which will be CORBA 2.0 compliant. The current shipping SOM specification is 2.1, which is CORBA 1.2 compliant.

Using an OpenDoc program

An OpenDoc program is typically made up of various OpenDoc components, which may have been developed in several different languages. (For now, FixPak 17 is required to support the OpenDoc runtime DLL.) The program uses the Object Request Broker (ORB) which has been in OS/2 since release 2.0, plus the OpenDoc runtime DLL which is free, may be freely distributed to others when bundled with your own software, and may be downloaded from ClubOpenDoc at:

http://www.software.ibm.com/clubopendoc.

This is similar to running a third-party REXX program such as VX-REXX, which uses REXX calls embedded in OS/2 plus a separate (large) DLL for additional functionality.

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