SIP Softphone Linux/Windows ?

[Henry Coleman]

Hi, it was great meeting you guys last Friday, unfortunately I had to 
leave early so I didn't have time to ask the following questions.   
1) I need a  free SIP  softphone that will run under Linux and Windows
2) Is there any way I can test the softphone to make sure they are okay?
Hope to meet again next month...
Thanks Henry 
[EMAIL PROTECTED]