Nautilus secure phone is a program that allows two parties to hold a secure voice conversation. Released in May of 1995, it ran on ordinary phone lines using a pair of modems (one at each end). It was meant as an answer to NSA's attempts to force "key escrow" on encrypted communication. Later versions of the program could also use TCP, i.e. the Internet. After the original developers abandoned the project, it was taken over by German maintainers. Actual development focuses on porting to the ARM platform and portability.
HOMER is a robust, carrier-grade, scalable SIP capturing system and monitoring application with hEP, IP Proto4 (IPIP) encapsulation, and port mirroring/monitoring support right out of the box, ready to process and store large amounts of signaling with instant searches, end-to-end analysis, and drill-down capabilities for ITSPs, VoIP providers, and trunk suppliers using SIP signaling.
The Ozeki VoIP Service Checker is a tool you can use for checking the availability of VoIP services. It can be used to verify whether a given service exists, see whether it can be reached from a particular network, and check whether the user details (such as the username and password) to access the service are correct. It was developed because many mobile Internet providers block VoIP traffic.
Speech synthesis for Asterisk using MS Translator text-to-speech service to synthesize speech and play it back to the user. It supports a variety of languages, local caching of voice data, and 8kHz or 16kHz sample rates to provide the best possible sound quality along with the use of wideband codecs.