SIP Clients

Enough of these started accumulating to warrant a node of their own:

(i.e., that you can configure to use with any provider)

Multi-Platform:

• X-Lite, a SIP softphone for Windows and Mac OS X
• eyeBeam, a SIP and H.323 videophone.
• SJPhone, another softphone (nagware)
• SflPhone - Linux-only for now, but stated as portable.

Windows

• Express Talk - Windows, freeware.
• sipXezPhone - lame name, ugly UI, but not half bad.
• Dialexia - unfortunate name, rather interesting Windows client. Time-based license.

Linux

• Twinkle - Qt-based.
• GnomeMeeting - evolving to SIP from H.323.
• minisip - Linux/PDA client.
• Cornfed - Linux-only. Looks simple and easy to use, but is closed-source.
• MythPhone - for MythTV.

Mac:

• Telephone
• MegaFon - not free, apparently pre-configured for its own service.

Multi-Platform:

• OpenWengo
• Ineen - rebranded eyeBeam with hard-coded settings, has a Mac OS X version.
• PhoneGaim - SIP (very badly) integrated into Gaim (the Windows beta completely trashed my IM setup)
• Gizmo - can't get it to work at all behind a firewall.

Windows:

• Pulver Communicator - Windows, integrated with IM and FWD. Also includes a (rather crummy) RSS aggregator. Can be unlocked for other SIP providers, but that doesn't rate it as an open client.
• Sapo - mixed Jabber/SIP IM client with voice and video support.

• Tapioca, a SIP/H.323 client library written in C.
• SIPshare, a P2P file sharing application using the NIST implementation.