3CX VoIP Phone System for Windows Free edition is an Office Phone System/IP PBX that completely replaces a proprietary PBX, supports standard SIP soft/hard phones from any vendor, VoIP service providers & traditional PSTN phone lines. Developed for Windows, it is easy to install, configure and manage via web-based config. Eliminates phone wiring, allows hotdesking & roaming, saves on call costs and includes auto attendant. Download FREE edition!