The Open Group offers a wide range of publications. A set of quick links into the catalog follow:
Access to freely available publications downloads requires an Open Group web ID, which can be freely obtained by registering at the "Login" link at the top of the page at www.opengroup.org. To obtain access to Members only publications you must be an employee of an Open Group member organization and your web account needs to have the appropriate member role assigned to it. You can check your roles at www2.opengroup.org/ogsys. The full list of Open Group members is available here (pdf).