Bloom fading from Posix rose as open focus shifts - the Portable Operating System Interface standards - includes a related article on Northwest Natural Gas's project to migrate from a mainframe to a client/server environment

Software Magazine, March, 1994 by Jerry Cashin

The IEEE specifications still provide essential services to open systems, but the standards come up short as focus shifts to systems and network management functions

The Portable Operating System Interface (Posix) family of standards is approaching the end of its first decade of existence. As standards go, Posix is "long in the tooth." As is often the case when birthdays approach, some industry observers are reflecting on what Posix has accomplished, and where it is heading.

Of the many standards professing to support open systems, Posix may be the most comprehensive, at least among those hatched by an official standards organization. Developed by the Institute of Electrical and Electronics Engineers (IEEE), Piscataway, N.J., Posix comprises more than two dozen specifications designed to enhance application portability. The specs represent one of the first salvos of the open systems movement, along with Open Systems Interconnection (OSI), the Manufacturing Automation Protocol (MAP), the Technical and Office Protocol (TOP), and the Government OSI Protocol (Gosip).

Yet, observers say, the bloom is off the Posix rose. "Posix is good in those areas that it covers, but new issues must be addressed," said Jim Isaak, the Nashua, N.H.-based standards information director for Digital Equipment Corp. (DEC), headquartered in Maynard, Mass. Isaak has long been involved in Posix standardization efforts at the leadership levels.

"New Posix projects dealing with subjects such as shared memory and realtime computing have recently been started," he added. "We urgently need system management specifications, and that effort is underway."

Isaak explained that viable open systems require many things. "Posix provides essential services to open environments, but there are other components outside its domain that are also necessary. Items like the Distributed Computing Environment [DCE], Windows standards and Unix unification efforts by X/Open all play a role," he said.

Coming to Posix's defense, Mary Lynne Nielsen, senior project editor at the IEEE, said that Posix has achieved credibility both in the U.S. and abroad during the last decade. "These standards have been in development for a number of years. Several have been approved and are familiar to a wide audience. The benefits of standards such as 1003.1 and 1003.2 are broadly recognized, thus promoting their acceptance," she said.

Vince Gritsch agrees that Posix is important to those seeking interoperability for their open systems. "Posix is a key to vendors who have non-Unix platforms," declared Gritsch, channel development manager at Hewlett-Packard Co., located in Cupertino, Calif. "The majority of boxes out there are still non-Unix. It is very important to have a Posix-type capability. Our goal is to provide portability and interoperability to non-Unix systems via our Posix offerings."

Indeed, some claim that Posix is the mainstay of the standards movement. Ruth Songhurst, vice president at Mortice Kern Systems (MKS) Inc., a prominent Posix original equipment manufacturer and product supplier headquartered in Waterloo, Ontario, Canada, calls Posix "the mother of all standards. It is well-accepted and integrated, successful to the point of being transparent," she declared.

Stephen Walli, senior technical specialist at MKS, said that Posix is at the core of XPG4 standards from X/Open. "It is a vendor-neutral solution, not a consortium creation," he stressed.

Vendor consortia have been largely unsuccessful in efforts to create standard open operating systems. One, Unix International (UI) Inc., formed by AT&T, Morristown, N.J.; Sun Microsystems Inc., Mountain View, Calif.; and Unisys Corp., Blue Bell, Pa., was disbanded late last year. The Open Software Foundation (OSF), Cambridge, Mass., has struggled in new areas after its operating system effort failed to gain wide acceptance. The London-based X/Open Co. Ltd. consortium recently renewed its effort to create standard Unix application programming interfaces (APIs) following the failures of UI and OSF.

These efforts to standardize open systems continue to miss a very elusive target. "The closer you come, the further away it gets" may sum up the first 10 years of standards work in this area. Though each of the open system standards efforts provided building blocks necessary to further the open systems movement, none of the initial projects has had the impact envisioned at their conception. This is not to say that Posix, OSI, MAP and the rest are dinosaurs. While they have lost momentum to varying degrees, each continues to evolve--particularly Posix.

Among more recent open system efforts are the X/Open Portability Guide (XPG3/4) from X/Open, whose U.S. operation is based in Menlo Park, Calif.; Application Environment Specification (AES) from the Open Software Foundation; and the Common Open Software Environment (Cose), a joint effort from Hewlett-Packard; IBM; Novell Inc., Provo, Utah; The Santa Cruz Operation (SCO) Inc., Santa Cruz, Calif.; SunSoft Inc., Mountain View, Calif.; and others. Most of this work has been united under the banner of the Spec 1170 universal API standard announced last September. And there will certainly be more initiatives addressing other complex problems in the near future.