Stanford CoreNLP, a Java suite of core NLP tools
MyTTS is a free text-to-speech (TTS) software, 100+ languages
Free open source speech synthesizer for Russian and other languages
OSX Styled Powerful Audio Workstation
Free and open source text-to-speech software
Resources for speech processing in Brazilian Portuguese
This project includes basic NLP and DSP techniques for Text-to-Speech
Now With Speaking Words you can convert all documents in Audio Files
Text-to-Speech System for Galician and Spanish