The most affordable CRM system according to Capterra
Unified Communications System - PBX System
Project about FusionPBX on Live Medium
Kazoo Live Medium. From Null to a Full Featured PBX on minutes
Infinity is a panel for Windows that monitors asterisk PBX
Cyber-wrt pbx is embedded system in DD-Wrt router
CRM system based on vtiger, adapted to Polish companies.