Swish - Insanely great window management
Zoiper - Cross-platform VoIP softphone dialer for SIP and IAX systems
Starters - Hacker news for sports tech
Linphone - Linphone is an internet phone or Voice Over IP phone (VoIP).
Scorum.com - Become a paid sports blogger
MicroSIP - MicroSIP is a free portable SIP softphone for Windows based on PJSIP stack.