x-lite, x-pro: A SIP client for Windows; Mac OS and Windows CE, . A really nice SIP UA with a lot of features. The light version is free and really rocks, the pro version not. Supports multiple proxies.
MiniSIP: An open source SIP user agent for Linux which runs on PDAs. It is based on several libraries, including libmsip, a C++ SIP stack. Homepage: .
OpenWengo: A Windows softphone based on Qt and eXosip. Open Source..
KPhone: A SIP Softphone for Linux (KDE); Homepage:
Microsoft portrait: Windows SIP client that supports Audio, Video and IM. Uses RTC API 1.2 and therefore has poor compatibility with other SIP clients..
Ubiquity User Agent: Java based SIP Client for Windows, very useful, you have to register (free) to get an license; Homepage:
EZ-Phone (Evaluation Version): SIP Phone for Windows; Homepage:
MySIP: SIP User Agent from Siemens; Homepage:
SJPhone: SIP and H.323 Softphone for Windows, Linux and PocketPC from: . There must not be another SIP client running on port 5060 or the SJPhone won't work.
Linphone: A SIP Softphone for Linux (GNOME), needs libosip ans oRTP; Homepage:
Vovida: Complete SIP Suite for Linux (Uaser Agent, Proxy, ...), very, very big software contruct; Homepage:
Siphon: Linux SIP Softphone; Homepage:
ActXPhone: An ActiveX-Control SIP Softphone based on the Microsoft Real Time Communications (RTC) API..
sipXphone: Part of pingtel's open source releases for VoIP. License: ; Homepage: . This softphone also requires lots of other libraries from the sipX... software at sipfoundry.org.
SIPPS: SIP softphone with answering machine and a lot of features. They have also integrated support for nikotel.com for SIP-PSTN termination.. A Demo for testing is available. The configuration is a bit weird (what's the difference between a proxy and a redirect server?).
MSN Messenger: Microsofts Messenger, Version 4.6 allows also connections to other SIP servers than microsofts one. Nice design, works very well. Can be used with the SIP service of iptel.org. Homepage: ; local for Windows NT (2000).
MSN Messenger: Microsofts Messenger, Version 4.7 allows also connections to other SIP servers than microsofts one. Nice design, works very well. Can be used with the SIP service of iptel.org. Homepage: ; local for Windows XP.
Shtoom: An open source, cross plattform SIP client written in Python. License: ; Homepage: .
Cornfed SIP-UA: A SIP user agent for Linux. License: Free for non-commercial use (binary distribution); Homepage: .
PhoneGaim: The multiplatform, multiprotocol IM client GAIM was extended with VoIP (linphone based) by linspire/sipphone. It's open source! At the moment it's in a beta status and supports only sipphone.com as SIP proxy, but as the source code is also available, you can change this by yourself ;-). Homepage: .
SFLphone: A multiplatform, open source SIP user agent. It is based on several libraries: cc++, ccRTP, osip2+eXosip. Open Source. Homepage: .
ENUM softphone: An ENUM enabled SIP client based on the RTC API. Open Source. Homepage: .
Phoner: A Windows softphone which supports dialing via an internal ISDN adapter (CAPI), TAPI or SIP. Freeware. Homepage: .
Twinkle: A Open Source Linux softphone based on Qt and ccRTP. Homepage:.
BOL SIP Phone: A Windows softphone based on the MS RTC API and WinStun. Homepage:.
sipXezPhone: A Windows/Linux softphone based on the sipXtapi. License: LGPL, Homepage:.
sillyAnt: The first freely available SIP softphone for Symbian Series 60, unfortunately this SIP phone is locked to . Homepage:.
PJPHONE: Windows SIP phone based on the PJ... stacks. License: LGPL; Homepage:.
