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Whither POSIX?
A Proposal From the Open Group

Dr. Petr Janecek <>, Director of Standards Development at The Open Group,presents a proposal for closer collaboration with The Open Group.

This article is based on a draft proposal for coordination of standardization activities between the IEEE Portable Applications Standards Committee (PASC) and The Open Group (TOG). The proposal will be discussed by the members of the ad hoc committee established last October by IEEE PASC Sponsor Executive Committee (SEC) and subsequently, if appropriate, by the SEC itself. At this stage, it is merely a proposal for discussion, but views are welcome!


This proposal aims at eliminating duplication of industry standardization efforts in the area of open operating systems and eventually eliminating the need for a single supplier to provide different products complying with two very close but not (yet) identical industry standards, POSIX and UNIX.


The interest in standardization of open operating systems has peaked and is rapidly tailing off, with the industry moving its standardization resources into new areas, in particular, the Global Information Infrastructure.

All standards organizations have been feeling a falling interest, meeting attendance, and membership.

The open operating system standards established through the activities of IEEE PASC, in particular the POSIX.1 and POSIX.2 groups of standards, are stable, and there is little industry interest in anything more than their maintenance (i.e., error removal and interpretations). Some niche markets are still interested in profiling and further development of special features of POSIX (e.g., POSIX for embedded systems), but vendors serving the general market do not wish to have to implement such new features as part of their basic operating systems offering. POSIX has become mature.

The UNIX operating system, the trademark to which is owned by The Open Group (UNIX and the "X" device are registered trademarks in the US and other countries) has become a de facto standard reflecting industry's choices in practical implementation of POSIX "core" standards. The UNIX definition recognizes the POSIX standards as over-riding ones but is tighter, so that a UNIX-compliant system automatically complies with the POSIX standards while the opposite is not true.

The two standards, POSIX and UNIX, use different style and format, but are maintained by essentially the same limited group of the best of industry experts and are implemented by the same vendors. There is little reason to have the same group of people participating in two different forums carrying out what is essentially the same task.

The time has come to optimize and merge relevant standardization activities of the two bodies, IEEE PASC and TOG, while making sure that no constituency feels disenfranchised.

Industry`s financial support makes it possible for The Open Group to provide professional standardization support services, including full-time managers and editors, as well as Web-based and other publications. Such facilities off-load volunteers from the administrative and routine work and secure a high speed of development.

Industry support also makes possible additional services building on the results of the standardization effort: development of test suites and management of testing services, branding of compliant systems, and professional marketing services. It is therefore felt that TOG could provide a good professional home for future POSIX as well as UNIX standardization activities.


Options for collaboration between IEEE PASC and TOG depend on the degree of overlap of the current activities, the two organizations' plans for future work, and IEEE's interest in new services. The Open Group can offer IEEE and PASC the following:

  • Maintenance services for approved standards (.1 and .2 families)
  • Home for ongoing 1003.1/.2 projects
  • Home for projects in specialized areas
  • Testing services Branding services
  • Publications Services

Maintenance Services
for Approved Standards

The following completed standards are in maintenance mode (i.e., error correction and interpretations) and suitable to be handled via an email-based maintenance structure of expert review groups provided by TOG, not requiring physical meetings:

  • POSIX.1 System Interface
  • POSIX.1b Realtime
  • POSIX.1c Threads
  • POSIX.1g Protocol Independent Interfaces (Sockets and XTI)
  • POSIX.1i Fixes to .1b (Realtime)
  • POSIX.2 Shell & Tools
  • POSIX.2a User Portability Extensions
  • POSIX.5 Ada binding to POSIX.1
  • POSIX.9 FORTRAN binding to POSIX.1

The mechanism could be implemented by opening up the membership of TOG base group to interested PASC members as belonging to the existing category of "invited experts."

Home for Ongoing 1003.1/.2 Projects

The following core standards are still under development and could be handled via broadened participation in the Base Working Group of TOG:

  • POSIX.1a System Interface Extensions
  • POSIX.1n Fixes to 1003.1/1b/.1i/.1c
  • POSIX.2b Additional Utilities
  • POSIX.18 POSIX Profile

The same mechanism as above, namely opening up the membership of TOG base group to interested PASC members as belonging to the existing category of "invited experts," can be applied here.

Home for Projects in Specialized Areas

The following are some of the 1003 standards under development that cover specialized areas of interest to large and important customers. Although TOG currently has no similar activities, it could handle them through establishing new TOG working groups with open participation. The funding would have to come from the participants paying a meeting attendance fee of the same kind they today pay to PASC.

  • POSIX.1d and POSIX.1j Additional Realtime Extensions
  • POSIX.1h Fault Tolerance
  • POSIX.1m Checkpoint/Restart
  • POSIX.21 Realtime Distributed Systems Communications (LIS)

Testing Services

The Open Group has the first complete POSIX Conformance Test Suite family
in the industry for the whole of POSIX.1­1996 and POSIX.2­1992.

Further, The Open Group recently introduced Validation Services for FIPS 151­2 (POSIX) in response to the termination of NIST validation services. TOG's service is based on NIST procedures and NIST's PCTS test suite.

Branding Services

The Open Group's UNIX Brand provides to customers a legally binding guarantee of a branded product's compliance with the UNIX definition now as well as in the future. A vendor can obtain as part of the UNIX Brand a certificate that includes the FIPS certification. Branding of POSIX-compliant systems would be possible.

Publication Services

The Open Group makes its specifications publicly and freely available on its Web site. In addition, CD-ROM and electronic and paper publications are provided. The Open Access mechanism currently under development makes access and marking-up of documents over the Web easy and suitable for review by groups of experts.


Several issues still need to be worked out. In particular, the decision-making process in TOG is based on organization representation, while that in PASC balloting groups is based on individual participation. One possibility to solve this might be that TOG would consider the current PASC members interested in continuing their activities within TOG to be a group with the right to institutional representation (i.e., voting rights) to the Base Working Group. This is exactly akin to the existing system, ISV and customer

councils. The members of our Customer, Software Vendor, and System Councils vote in ballot reviews through elected representatives who are charged with representing the respective council's consensus. My idea is that the POSIX members would become another "council" with one guaranteed vote. Of course, companies that are already voting members do not go through this process.

The other area that requires further thought and resolution is intellectual property rights. All existing material is copyright of the IEEE and is not currently freely available. How do we deal with the issue of TOG modifying this material? How does it get published? I believe these are not insurmountable hurdles.


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First posted: 29th January 1998 efc
Last changed: 29th January 1998 efc
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