Blink (http://icanblink.com) is ok as a client. I'm not 100% on the interface, but it does seem to work well without crashing. It's gpl, and it does seem to have some momentum behind it.
There's one called simply "Telephone" which is very simple, just a textbox to call. No contact list or anything. (well, it wasn't much in december, since then they've moved from code.google to github: https://github.com/eofster/Telephone)
Gizmo5 is a crashy piece of ...something. It's the only app I've ever had on osx that has crashed so hard it's needed to be reinstalled. Several times. OTOH, you can't get it anymore, and Google is shutting down the sip service behind it.
There's one called simply "Telephone" which is very simple, just a textbox to call. No contact list or anything. (well, it wasn't much in december, since then they've moved from code.google to github: https://github.com/eofster/Telephone)
Gizmo5 is a crashy piece of ...something. It's the only app I've ever had on osx that has crashed so hard it's needed to be reinstalled. Several times. OTOH, you can't get it anymore, and Google is shutting down the sip service behind it.