Telepati SIP Phone Freeware
Telepati SIP Phone Freeware allows you to make PC-PC phone-phone calls over the Internet. Developed using Research Labs VOIP SIP Phone SDK, this free soft phone brings SIP protocol support for ActiveX. With this phone once you set the gatekeeper proxy with the username and password from your... Now VOIP open source projects have made it easier to implement a customized VOIP Solution eliminating costly PSTN lines. ... Though this implementation might turn out fairly complex, our VOIP Implementation Team at Research-Lab will guide you remotely for the same.
http://www.bandwidthsaver.com/downloads/telepati.zip - 1Mb - Download - Screenshot

VSoft3
The VSoft Phone is a simple to use internet telephone system that can reduce your call costs. It uses the latest technology to let you make calls to friends, family, and business associates anywhere in the world without any chunky telephone equipment. ... VSoft features includes unlimited free VoIP to VoIP call (PC to PC), free video call, low cost VoIP to home/mobile call, send SMS, confrence, SMS to call, VoIP bridge. ... The VSoft Phone utilises a Broadband internet connection to allow a user to make VoIP calls to any phone number worldwide.
http://www.mobif.com.my/Download/VSoft3.3-setup.exe - 4Mb - Download - Screenshot

VOIP Phone Buddy for SKYPE
VOIP Phone Buddy for SKYPE VOIP Phone Buddy for Skype adds automatic telephone dialling to almost any windows application, using SKYPE VOIP telephony, including Microsoft CRM, Microsoft, Access, Microsoft Outlook, Goldmine, ACT, other CRM and Accounts packages etc. ... Simply move the cursor to a phone number and press the Hot Key to activate "VOIP Phone Buddy for Skype" phone dialer. ... The VOIP Phone Buddy for Skype and Jajah dialer then looks at the phone number, where the cursor was previously, and formats the international country code automatically.
http://urlcut.com/voipphonebuddy.exe - 2Mb - Download - Screenshot

3CX VOIP Phone for Windows
Free VOIP / SIP phone. Use your PC as a phone. Works with any SIP / VOIP provider/ phone service. Use instead of the soft phone provided by your VOIP provider which locks you into their VOIP phone service. Easy to use interface includes dial pad and buttons to transfer or forward a call. ... * Search using ENUM * Installation provided as MSI for easy deployment 3CX VOIP Phone for Windows also functions as a client for 3CX Phone System for Windows, a software-based VOIP PBX that completely replaces a traditional proprietary phone system.
http://www.3cx.com/VOIP/3CXPhone.exe - 1Mb - Download - Screenshot

SIP Phone DLL
SIP Phone DLL allows to make PC-PC, PC-phone, or phone-phone calls or create Instant Messaging (IM) sessions over the Internet VOIP SIP Phone SDK brings protocol support for ActiveX. With this SDK one can create a simple program to connect and start speaking with anyone with a direct IP Address... VOIP SIP DLL Soft Phone SDK brings SIP protocol support for ActiveX. ... Now VOIP open source projects have made it easier to implement a customized VOIP Solution eliminating costly PSTN lines. ... With this SDK one can create in minutes a VOIP phone program to connect and start speaking with...
http://www.ipchip.com/downloads/sphone01.zip - 3Mb - Download - Screenshot

Express Talk VoIP Softphone
Express Talk is software that works like a telephone to let you make calls from your PC. With Express Talk you can call anyone on the internet who has installed Express Talk (or any other SIP voip softphone). Calls are free. You can also call ordinary telephone numbers anywhere in the world if... Features: ~ Lets you make internet phone calls free direct PC to PC, or PC to phone via a VoIP SIP gateway provider. ... Within minutes you will be able to setup the software and start making phone calls.
http://www.audiochannel.net/software/talk.zip - 430Kb - Download - Screenshot

Quorum Call Conference Software
Quorum is software which runs as a phone conference server on any Windows PC. Callers dial into the server to join telephone conferences. Callers can connect to a conference call using either standard or VoIP lines on external telephone numbers or through an office phone system. ... ~ VoIP calls can be made using free VoIP SIP Service Providers saving call costs if they are an issue. ... ~ Easily allocate new conference IDs on the phone. ... ~ Can connect to ordinary phone lines (or analog PBX extensions) directly using telephony devices.
http://www.audiochannel.net/software/quorum.zip - 947Kb - Download - Screenshot

Embedded VOIP SIP Developers Kit
Embedded Windows CE VOIP Developers Kit is your embedded telephony solution for developing software/hardware to enable device to device phone calls using SIP/H323 phone right at the electronics level. The design is based on Hybrid Combination of RFC SIP Protocol and Windows RTC and is today... dll Make DEVICE-PC, PC-DEVICE, PC-Phone, or phone-phone calls or create Instant Messaging (IM) sessions over the Internet on Windows CE Both voice and video calls can be established on DEVICE-DEVICE calls.
http://www.ipchip.com/downloads/wincevoipsip01.zip - 2Mb - Download - Screenshot

One4000IP
One4000IP, is more than a Netphone that lets you take advantage of free broadband VoIP calling with premium voice quality as well as super low worldwide rates to regular phones without changing your operator. Call from your PC to other PC? s for free or call to regular fixed phones and mobiles... You can call to any PC with a SIP net phone/ soft phone, not just the ones with One4000 installed. ... Choose from which one of your registered phone numbers you want to make your call by clicking on one of the buttons: Phone, Mobile or PC.
http://www.one4000.com/download/one4000IP_setup.zip - 5Mb - Download - Screenshot

Axon Virtual PBx System
Axon is a virtual PBX designed to manage calls within a business or call center environment. Any business, whether small or large, can now implement a scalable PBX solution with an existing PC which connects to phone lines and extensions using VoIP technology. ... ~ Links directly to VoIP services for your external lines (with cheaper calls). ... ~ Works with hardware type VoIP extensions which just plug into the LAN (eg. ... See Recommended VoIP Gateways for more information. ... ~ If no VoIP services are available can also link to ordinary external lines with FXO adapters.
http://www.audiochannel.net/software/pbx.zip - 323Kb - Download - Screenshot