POSIX® Certified by IEEE and The Open Group is for products meeting the IEEE POSIX standards.

Welcome to the POSIX® Certification web site

The POSIX®: Certified by IEEE and The Open Group certification program is a voluntary program, but is required of suppliers who wish to use the POSIX® trademark. Certification is open to any product meeting the conformance requirements. Once a supplier has achieved certification for a product, they are permitted to use the trademark in connection with that product.


The POSIX®: Certified by IEEE and The Open Group certification program is administered on behalf of the IEEE and The Open Group by its designated Certification Authority, The Open Group. IEEE is the designated trademark licensing authority for the program.

The following defines the conformance requirements against which products can currently be certified:

1003.1™-2016 Base

NEW: 1003.1™-2016 Base certification is for platforms providing services that conform to IEEE Std 1003.1,2016 Edition (also known as POSIX 1003.1). This is a rich multi-user, multiprocess environment supporting interactive users

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1003.1™-2003 Base

1003.1™-2003 Base certification is for platforms providing services that conform to IEEE Std 1003.1-2001 (also known as POSIX 1003.1). This is a rich multi-user, multiprocess environment supporting interactive users.

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PSE54 Multipurpose Realtime 1003.13™-2003 System

PSE54 Multipurpose Realtime 1003.13™-2003 System certification for operating system environments providing realtime services based on IEEE Std 1003.13 Profile PSE54. This supports applications portability at the source code level and includes the provision of a standard operating system interface and environment, including a full file system implementation and support for multiple users.

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PSE52 Realtime Controller 1003.13™-2003 System

PSE52 Realtime Controller 1003.13™-2003 System certification is for embedded operating system environments providing realtime services based on IEEE Std 1003.13 Profile PSE52. This supports applications portability at the source code level and includes the provision of a standard operating system interface and environment, which includes a simple file system implementation, one implicit process with threads support.

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