Bayonne is the telephony server of the GNU project. It offers a script-driven threaded multi-line state event telephony service on GNU/Linux, xBSD, and Microsoft Windows for building voice response systems, and uses telephony plugins for runtime driver configuration. It also features "TGI" for making Perl applications "telephony aware". It may be used to build telephony-based system administration, home automation, automated attendant, v-commerce, and voice messaging systems.
mptc is a Perl script to help you work out whether you're on the cheapest mobile phone network/tariff for your phoning habits. You feed it an itemised phone bill and tariff pricing information, and it will tell you how much that bill would have cost on different tariffs. So far it only supports UK network pricing systems, but could easily be extended and applied in other countries.
PreViking is a telephony daemon written in C. It has been designed with a modular structure that easily allows the addition of different services and the support of different hardware. Current services include a calling card service and a call- back service. PreViking provides an API which includes many functions to do different telephony operations such as call switching, playing/recording messages, and listening/playing DTMF.
PyGCID is a graphical CallerID application written in Python with the GTK toolkit. It uses an external program to fetch numbers from your CID hardware. It maintains a small database with the incoming calls, and has the ability to store a comment and a note on each call. It can also dial the numbers using an external program, and run a specific program for each number (for example, you can play different sounds for different numbers).
VOCP is a complete messaging solution for voice modems, with voicemail, fax, email pager, DTMF command shell and Text-to-Speech support, 4 graphical interfaces, and a Web interface. Callers navigate the system using a touch-tone phone and may send and receive faxes, voice mail, and pager messages, listen to text/HTML email messages, or execute configured programs on the host and hear the resulting output.