phpivr is an Asterisk AGI application which uses PHPAGI to organize Interactive Voice Responses. It doesn't need extensions.conf changes and dialplan reloading if you want to modify the IVR menu, it reads phpivr.conf on the fly. It supports unlimited levels of IVR menus. It is a standalone tool (you do not need to install FreePBX with all its functionality), does not require additional exotic libraries, and is easy to integrate into your own application.
WikiPBX is a PBX Web interface for FreeSWITCH. Multiple "accounts" are supported per server instance: each account is effectively a completely independent PBX. Configuration is layered so that XML files go on top of what is stored in the database. This allows you to use a database, but stays out of your way if you choose to use flat files. Extensions, SIP endpoints, and gateways can be configured via a Web interface. Live calls can be viewed, hanged up, and transferred. Call history (CDR records) can be viewed over the Web interface. There is a Web interface for managing IVRs. "Sound clips" can be easily recorded for use in dialplan or IVRs. Audio or text-to-speech can be injected into live calls.
Scopserv Communicator is an audio/video Internet phone and instant messenger that supports some of the most popular VoIP and instant messaging protocols such as SIP, Jabber (XMPP), AIM/ICQ, MSN, Yahoo! Messenger, and a whole lot of other useful features. ScopServ Communicator is based on the SIP Communicator softphone.
Billion PBX is IP phone system that uses the SIP protocol. In addition to voice calls it supports call forwarding, voicemail, callback, and much more, and features simple installation and configuration, reliability, low hardware requirements, and a flexible pricing policy. Its main features are subscriber registration by SIP Registrar and RAS protocols, call routing by SIP and H.323, call authorization, subscriber self-service, Call Data Records (CDR), embedded rating and billing, integration with external billing systems, NAT traversal, IVR, report generation, and a convenient administrative Web interface allowing remote management.
Billion Softswitch works as a switchboard in SIP/H.323 VoIP networks, proxying both signalling and media streams while performing cross-protocol conversion and even media stream transcoding. It integrates advanced call routing features as well as embedded compact billing system. It supports subscriber registration by SIP Registrar and RAS, call authorization, call data record (CDR) list maintenance, external billing system interfaces, NAT/firewall support, and report generation, and is easy to install and maintain.