The 3.0.2 version of Mac2Speech for Mac was provided as a free download on our website. The software lies within System Tools, more precisely Automation. The actual developer of this software for Mac is Techcasita Productions.
From the developer:
Mac2Speech is a speech synthesis server for OS X and macOS Sierra, allowing you to use your Mac as a text-to-speech server, converting text strings into MP3 voice sound files on the fly. A web user-interface allows for rapid testing and experimentation with different languages and voices.
You may want to check out more software for Mac, such as iPAD, Bulldog or Launch!, which might be related to Mac2Speech.