Hewlett-Packard Co begins its planned transfer over to Object Management Group Common Object Request Broker Architecture 2 specifications with release 5.0 of its Distributed Smalltalk, DST, development environment this week (CI No 2,696). DST 5.0 includes Common Object Request Broker Architecture 2’s Internet Inter-Object Request Broker Protocol, IIOP, which is designed to enable objects and applications to interoperate over a network with other applications that conform to the Object Group’s Common Object Request Broker Architecture 2 and is described as a three-tier, multi-language, multi-system application development system. Last year, Hewlett-Packard and Digital Equipment Corp lobbied unsuccessfully for use of a rival Open Software Foundation Distributed Computing Environment-based Common Inter-Object Request Broker Protocol, CIOP, as the key interoperability protocol for the Object Group’s architecture (CI No 2,554); IIOP can be implemented upon TCP/IP, CIOP and other transports.

Object classes

DST 5.0 is a bundle of software services that work in conjunction with ParcPlace Systems Inc’s VisualWorks 2.0 Smalltalk implementation on HP-UX, SunOS, Solaris, AIX, Windows, NT and OS/2. Version 5.0 of the development environment includes a Common Object Request Broker Architecture 2-compliant Smalltalk Object Request Broker, transaction and concurrent Common Object Request Broker Architecture services, an Interface Definition Language generator and some 150 object classes. VisualWorks’ machine-dependent hardware, operating system, network and user-defined elements are encapsulated as a ‘virtual machine’ definition, upon which machine-independent tools, 500-odd object classes and DST reside. For backwards compatibility, the environment’s original protocol, the Network Computing System remote procedure call, NCS RPC, is included alongside IIOP, although it’s completely incompatible with the version that features in the Software Foundation’s latest Distributed Computing Environment release. Hewlett-Packard will add CIOP to the DST request broker in a subsequent release. When its C++-based Common Object Request Broker Architecture 2 Object Request Broker-Plus request broker is released – development kits are promised for the end of the year, production copies in the first quarter – Hewlett-Packard said programmers will be able to create different parts of an application in different languages on multiple systems. A client component could be created using DST on Hewlett-Packard or Sun Microsystems Inc boxes, and the server could be coded in C++ using HP SoftBench. DST 5.0 will work across other Common Object Request Broker Architecture 2 request brokers and will be extended to support distributed development and partitioning in conjunction with other development systems compliant with the architecture, including Hewlett-Packard’s Taligent Inc investment and NeXT Computer Inc’s OpenStep. Hewlett-Packard will demonstrate full Common Object Request Broker Architecture 2 interoperability with a bunch of other vendors at next week’s Object World show. The DST 5.0 Object Request Broker includes Smalltalk binding and interface repository standards, plus other mechanisms for building distributed applications which share objects. Based on X/Open Co Ltd’s transaction processing model, Common Object Request Broker Architecture Transaction services can be used to write transaction-based applications without having to create the transaction services themselves. They use a new subclass from DST RecoverableObject class and three new methods. Concurrency control (also used by the transaction service) mediates access to an object and administers locks on a resource. Applications using these services will run under the next release of current transaction processing monitor products that Hewlett-Packard expects will be object-oriented. A new Interface Definition Language generator enables developers to create code from push-buttons and menus, eliminating hand-coding. DST also extends VisualWorks for remote editing and debuggi

ng. Hewlett-Packard believes there will have to be a fundamental cultural change in favour of code re-use techniques before a market in which independent software vendors sell objects can emerge. In the meantime, object technologies will drive rapid application develo pment and easier upgrade and maintenance strategies, it thinks. The company expects Smalltalk environments to win Cobol programmers moving to objects while C++ will remain the performance engine for object systems. DST 5.0 costs $5,000 on Unix, $3,000 on personal computers – it requires VisualWorks from ParcPlace.