IBM Corp is really beginning to push its object-oriented development expertise and on June 16 it launches its Distributed System Object Model. Put simply, DSOM attempts to be a cross-system product that enables objects to work together, irrespective of the machine on which they run or the language in which they were originally written. The plain non-networked System Object Model first emerged with the launch of OS/2 Version 2.0 and is embedded in the Workplace Shell. System Object Model introduced developers to the technology and enabled them to take advantage of the objects built into the shell for their own use, implementing ‘inheritance’ quite nicely, so that developers can take, say, the folder object from the Workplace Shell and tweak it for their own use – to make a mail in-tray, for example. The technology provides a standard way of defining an object’s interface, based on the Common Object Request Broker Architecture’s Interface Language Definition; implements a run-time mechanism for transferring requests from one object to another and defines its own ‘language binding’ which, once implemented by compiler manufacturers should ensure that objects will be interchangable between System Object Model systems irrespective of the source language. To date IBM says that it has generic bindings that will that will work with any ANSI C or C++ compiler and IBM and MetaWare Inc are busily building support into their efforts so that programmers will be churning out System Object Model-compatible objects by default. Other support has come from Digitalk Inc which has announced SOM support in its Smalltalk/V and Parts object-oriented development environment, while Micro Focus Plc has made noises about building System Object Model support into its planned object-oriented Cobol. While the ability to share objects is useful, SOM as it stands is not without its glitches: in particular programmers found that to share objects with the workplace shell, their applications had to share its address space – which does not make for the most robust of systems. Distributed System Object Model aims to cure that problem, so that applications in different address spaces can work together. It is almost a by-product of the ability to run over networks, however it is this feature, rather than the promise of distributed objects that interests Laurence Shafe of Intelligent Environments Inc which has versions of its Application Manager client-server development tool for both OS/2 and Windows NT. The June 16 launch will see IBM officially unveil SOM Objects Toolkit for OS/2 with an AIX Unix implementation following hot on its heels. The Toolkit itself will contain the Distributed Systems Object Model implementation and the C++ compilers from IBM and MetaWare. A Microsoft Windows version is scheduled by the end of the year, with HP-UX following next year. Native support for the Distributed System Object Model will be added to the OS/2 Workplace Shell in a future release.
