Standardization Body	Note
	The Internet Engineering Task Force (IETF) is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. See also the list of IETF's efforts and documents related to Internet telephony.
	The International Telecommunication Union (ITU) is the leading publisher of telecommunication technology, regulatory and standards information. Its published H.323 standard for multimedia terminals in networks with non-guaranteed QoS is gaining increasing popularity in the world of IPT vendors. The H.323 is an umbrella for many other standards covering signaling, real-time voice transports, codecs, etc. The standards are available at Packetizer's site.
	Standards organizations and other related bodies have agreed to co-operate for the production of a complete set of globally applicable Technical Specifications for a 3rd Generation Mobile System based on the evolved GSM core networks and the radio access technologies supported by 3GPP partners (i.e., UTRA both FDD and TDD modes). The Project is entitled the “Third Generation Partnership Project” and may be known by the acronym “3GPP”. (Note that 3gpp anticipates use of SIP as telephony signaling protocol in all-IP networks.)
	The project "Telecommunications and Internet Protocol Harmonization over Networks" (Tiphon) has been established by the European Telecommunications Standards Institute (ETSI, well known for its GSM standards) to ensure that users connected to IP based networks can communicate with users  in Switched Circuit Networks (such as PSTN, ISDN, GSM, SS7). Tiphon documents are located here. Tiphon has also launched an initiative TIPIA (Tiphon IP-Telephony Implementation Association) to support interoperability of Tiphon-compliant products.

Consortia, Coalitions, Associations, etc.  

	SIP Forum is a non profit association whose mission is to promote awareness and provide information about the benefits and capabilities that are enabled by SIP.
	The mission of the International Multimedia Teleconferencing Consortium, Inc. (IMTC) is to bring together all organizations involved in the development of interactive, multimedia teleconferencing products and services to help create and promote the adoption of industry-wide interoperability standards. The IMTC is currently focused on multimedia teleconferencing standards adopted by the ITU and interoperability of products claimed to be ITU-conform. IMTC formed a Conferencing over IP (CoIP) Activity Group as a part of the IMTC Contributions. IMTC contributions are available here. The formet iNow has merged with IMTC. iNow! is a multi-vendor initiative established to quickly provide interoperability among IP telephony platforms. The iNOW! Standards-Based IP Telephony Interoperability Profile provides equipment vendors with the blueprint for chieving real world, revenue-generating gateway to gateway and gatekeeper to gatekeeper interoperability.
	The MIT Internet Telephony Consortium consists of member firms and selected academics who collaborate on research into technical, economic, strategic and policy issues that arise from the convergence of telecommunications and the Internet.
	The VON Coalition's mission is twofold: actively advocate the viewpoint that the IP Telephony industry should remain as free of governmental regulations as possible, and to educate consumers and the media on Internet communications technologies. (See also the list of members.)
	The Telecommunications Industry Association represents the telecommunications industry. It is also focusing on stadardization of IP phones and their particular features (TR-41.3.4. spec).
	CableLabs is a membership organization consisting of cable television system operators serving cable subscribers in the North and South America. Its mission is to plan and to fund research and development projects; to transfer relevant technologies to member companies and industry suppliers; and to serve as a clearinghouse in providing technological information to its members. It has established a project PacketCable  aimed at identifying, qualifying, and supporting Internet-based voice and video products over cable systems. Master-slave approach to iptel signaling is favoured.
	The Softswitch Consortium is the international organization for global cooperation and coordination of internetworking technologies in the field of internet-based real-time interactive communications and related applications. The purpose of the Consortium is to support rapid advancement of application development for the evolving Internet protocol networks which support both voice and multimedia communications. Internet protocol networks are built on distributed call control servers generally called "call agents," "media gateway controllers," "softswitches," and "media gateways". The Consortium  promotes worldwide compatibility and interoperability; identifying, selecting, augmenting as appropriate, the development and distribution of standard interfaces for "call agents," media gateways, and applications.
The Parlay Group	The Parlay Group's objective is to promote industry acceptance of the Parlay API, a specification designed to enable carriers and independent software vendors to write applications to provide services across wireless, Internet, and wireline networks. Faster time-to-market and less complex development cycles are some of the key benefits of the Parlay API. Founded in 1998, the Parlay Group focused initial development of its API on functions such as call control, messaging, and security. The current Parlay Specification paves the way forward in developing usable, real-world product implementations of the API. The current members of the Parlay Group are AT&T, BT, Cisco Systems, Ericsson, IBM, Lucent Technologies, Microsoft, Siemens AG and Ulticom. The specification has been published at http://www.parlay.org .
The JAIN Initiative	Organized by Sun in 1998, the JAIN initiative addresses the needs of next-generation telecom networks by developing a set of industry-defined APIs for Integrated Networks. Network services today are typically built using proprietary interfaces that inhibit the marketplace for new services. Members of the JAIN community have joined forces to define open APIs based on Sun's Java platform, thus allowing service providers to rapidly create and deploy new flexible, revenue-generating services. Information about the JAIN program can be found at http://java.sun.com/products/jain/ .

Other related organizations involved in standardization/promotion of Internet telephony are SIP Forum, TTT, VoiceXML Forum.

Today almost all major companies providing Internet services and products are getting involved in the emerging Internet telephony market (to name at least some of them: 3Com, Ascend, Cisco, Clarent, Ericsson, Hitachi, Intel, Lucent, Microsoft, Motorola, Netscape, RADVision, Siemens, VocalTec and many more). Many of them have declared strategic alliances (e.g. Cisco with Hitachi, Gric, HP, OzEmail; Ascend with Mind CTI; NetSpeak with Motorola).  See the list of products and Pulver.com's list of Internet telephony providers for more references.

Pulver.com, a leading Internet telephony consulting firm, collects all information on Internet telephony on its web-site, i.a. a list of IPT Telcos, recent publications, gateway providers and much more. Pulver.com also organizes the "Voice over Net" conference and administers a "VoN" website.

PictureTel Corporation administers a website about videoconferencing and telecommunications standards. The site is intended to provide the standards community with a single point of access to the many industry  activities associated with the development of videoconferencing standards.