VICIdial Contact Center Suite
The most affordable CRM system according to Capterra
Unified Communications Server
Unified Communications System - PBX System
Proximus Forum 700 pbx dial number management
Enterprise telephony recording and retrieval system
ERP, IP PBX, Accounting, CRM, Time tracking, and etc.
vTiger Freeswitch PBX Integration
Extend vTiger CRM to add FreeSWITCH support