Nearly anyone who requires voice oriented services like speech to text (STT) or text to speech (TTS) may benefit from the public voice exchange.
Privox was designed, however, with the developer in mind. It provides STT and TTS endpoints which support standard HTTP ‘post’ operations available in nearly all programming languages. It can also be accessed from the command line using the CURL command.
Typical applications include smart speakers, voice assistants, home automation systems, robotic control and basically anything you want to add a voice interface to. While Privox is written in the Python programming language, it is language agnostic and the APIs adhere to standard CGI conventions.