3CX

3CX is a software-based PBX supporting Windows, Linux, and cloud environments. It includes an auto-dialer function in certain editions, letting users create outbound call queues. The free edition provides limited concurrent calls and basic features, suitable for small call campaigns. A web client or softphone integration can handle inbound/outbound calls. 3CX also offers IVR, call queues, and presence management. By configuring dialer scripts, teams can run small telemarketing or follow-up campaigns at minimal cost. Larger deployments or predictive dialing require upgrading, but the free tier is a solid starting point.