opensips

OpenSIPS (Open SIP Server) is a mature Open Source implementation of a SIP server.

3CX Phone System

3CXPhone is a free VoIP phone available for Windows, iPhone or any Android based smart phone such…

8x8 Cloud Contact Center is a VoIP call center solution.

An open source telephony switching and private branch exchange service for Linux.

AsteriskNOW is the fastest way to get started building custom telephony solutions with Asterisk.

Switch is a cloud-based phone system built for Google Apps users.

Five9 provides cloud-based call center software for sales, marketing and support.

FreeSentral is a full IP PBX consisting of a Linux Distribution, an IP PBX and a Web Graphical User…

FusionPBX is an open source FreeSWITCH GUI.

Grasshopper enables entrepreneurs to build a virtual office that connects callers to employees, wherever they are.

Kamailio® (successor of former OpenSER and SER) is an open source SIP server released under…

The most advanced interface for managing Asterisk PBX with Multitenant and Realtime capabilities

PBX in a Flash is a PBX system based on Asterisk, FreePBX and CentOS, coming as an ISO download.

RingDNA is a provider of cloud based inside sales productivity and marketing intelligence software such as call tracking, dialers, and IVR.

Starfish PBX aims to be an open source alternative to Digium’s Switchvox.

Incredible PBX is a secure and feature-rich implementation of the Asterisk® PBX.

VitalPBX is a full-feature PBX (phone system) based on Linux and Asterisk.

Wazo is a unified communications platform based on Asterisk and focused on extensibility.

FreePBX is a web-based open source GUI that controls and manages Asterisk (PBX).