ANSI – American National Standards Institute
It provides access to timely and relevant information on the ANSI Federation and the latest national and international standards-related activities.

ATIS – Alliance for Telecommunications Industry Solutions
This is one of the world’s leading standards development bodies for telecommunications.

The Broadband Forum (formally “The ATM Forum”)

CEN – The European Committee for Standardization

Computer and Communication Entry Page
Entry point to the telecommunications Web structure. This site provides focused search categories in  "Standard Terms" and "Geographic" sections.

DMTF – Distributed Management Task Force, Inc.

ETSI – The European Telecommunications Standards Institute
The ETSI is a non-profit making organization whose mission is to determine and produce the telecommunications standards that will be used for decades to come. It is an open forum that unites 696 members from 50 countries, representing Administrations, network operators, manufacturers, service providers, and users.

IEEE-SA   – The IEEE Standards Association

IETF – The Internet Engineering Task Force Home Page

ITU – T Recommendations
List of ITU-T Recommendations. Those on NM are under E.41x and X series.
Normally you would need a subscription to get the full text of a Recommendation. Without subscribing you can still get the overview of the existing Recs.

  • ITU – TMN Roadmap Page
    This page is intended to be a gateway to standards information on Telecommunications Management Network for application developers, standards people, and others who have an interest in the TMN.

OMG – The Object Management Group
Information on the OMG activities and links to its objects definitions. Part of this information is relevant to interfaces in NM.

The Open Group

TMF – The TeleManagement FORUM
The TeleManagement Forum is a non-profit global organization of incumbent and new-entrant service providers, computing and network equipment suppliers, software vendors and customers of communications services. It provides leadership, strategic guidance and practical solutions to improve the management and operation of communications services. Information on SMART TMN, SPIRIT and definitions of Managed Objects resulting from its activities.

The SimpleWeb
This is a site providing links and information on network management, including software, RFCs and tutorials. Mostly focussed on SNMP. It provides links to a variety of vendors and network management servers managed by European Universities.

The Simple Times
An openly-available publication devoted to the promotion of the Simple Network Management Protocol (SNMP). It is maintained as a joint activity of the University of Twente and the Technical University of Braunschweig.

X.Org
This is the worldwide consortium empowered with the stewardship and collaborative development of the X Window System technology and standards.