The most affordable CRM system according to Capterra
Unified Communications Server
Unified Communications System - PBX System
Asterisk based VoIP pbx appliance
Enterprise telephony recording and retrieval system
ERP, IP PBX, Accounting, CRM, Time tracking, and etc.
VozBox. Asterisk VoIP PBX.
vTiger Freeswitch PBX Integration
Cyber-wrt pbx is embedded system in DD-Wrt router
Asterisk and Yate (VoIP PBX) Scripts and Libraries
predictive dialing for vTiger using asterisk
CRM system based on vtiger, adapted to Polish companies.