Asterisk - An open source telephony switching and private branch exchange service. Allows peer-peer calling using a variety of voice over internet protocols.

Asylum Telecom - VoIP provider for business and residential customers. No service charges.

BroadVoice - VoIP provider offers full feature set with voice mail, caller ID, etc. Requires supplied broadband phone adapter.

CallDaddy - Pre-paid VOIP services. H.323 IP phone, gateway, gatekeeper, NetMeeting or any other H.323 compliant terminal necessary.

Calleveryone.com - A full featured VoIP/broadband phone to phone service primarily for calls within the US.

Callserve - PC-to-Phone service for outbound calls only. Software download required.

Dial2Home - VoIP service for phone-to-phone with adapter or peer-to-peer.

Dialpad Communications, Inc. - Offers monthly billing and pre-paid PC-to-Phone VoIP services. Also supports broadband telephone adapter for use without PC.

Dow Networks - Provides Voice over IP and telecom service to international clients.

Efonica - Prepaid system for PC-to-phone and web initiated phone-to-phone using VoIP.

Free World Dialup - Community network allowing calls to toll free numbers in the US, Japan, UK and Netherlands. Peer-peer calling to other members.

iConnectHere - Offers VoIP-based PC-to-Phone, Broadband Phone and Calling Card services.

IPCB.net - Softswitch services such as routing, billing as well as VoIP call termination.

ISPhone Inc. - Wholesale voice over internet services.

MeaPhone - PC to phone service based in Thailand. Software download required.

Mywebcalls - PC-Phone or device-to-phone United Kingdom based service.

On Instant - PC-to-PC only isntant messaging service with VoIP features including live voice, voicemail and CRM tools.

One Unified Net - A communications infrastructure provider includes IP systems, services, softswitches, and phones.

Packet8 - Voice over internet direct dial service without a PC. Owned by 8X8, Inc.

PC2call - PC-phone internet voice service provider based in the United Kingdom.

Redshift Networks - Operates and builds international carrier networks using VoIP and TDM circuit transmission technologies.

RhinoBell - PC to phone, phone to phone using device, voice over internet calls.

SIPphone Inc. - Peer-peer calling service. Requires SIP adaptor and phone.

Skype - Peer to peer internet voice service. Requires PC for both callers.

Super Technologies, Inc - Offers flat-rate unlimited calling within USA & Canada. Uses analog telephone handsets via broadband telephone adapter.

Talafone - Canadian based provider of PC-to-phone and IP phone services and hardware.

v59 - Use dial-up and talk everywhere with our VoIP service

Vinculum Communications - VoIP wholesale international termination services provider.

VocalNet - VoIP provider offering residential and business plans.

Vodawave - Residential and enterprise VoIP plans plus gateways, gatekeeper and billing software.

Voice over IP Calculator - Free VoIP resources, including online bandwidth calculators, white papers, books, a directory and a forum.

Voiceglo - VoIP service offering free and paid plans. Some plans require phone adapter or USB phone with an Internet-connected computer.

VoicePulse - VoIP service offering phone-to-phone with device. Various features and calling plans.

VoIP Providers List - Information exchange for VoIP partners offering minutes termination and origination, as well as hardware and software trade.

VoIPOnline - Voice-over-IP news, supplier directory and chatrooms for discussing related industry topics.

VoipXchange - B2B VoIP exchange platform for carriers to buy/sell excess capacity on VoIP networks covering call termination in 250+ countries. No-fee membership required.

Vonage - Provides voice over internet local dial-tone service. No PC required. Uses analog telephone with broadband telephone adapter.

WhistlerTel Inc. - US provider of broadband internet phone service and voice over IP (VoIP) solutions.