Amazon Polly is described as 'Uses deep learning technologies to synthesize natural-sounding human speech, so you can convert articles to speech. With dozens of lifelike voices across a broad set of languages, use Amazon Polly to build speech-activated applications' and is a Text to Speech service in the development category. There are more than 25 alternatives to Amazon Polly for a variety of platforms, including Web-based, SaaS, Mac, Windows and Android apps. The best Amazon Polly alternative is VoiceCraft, which is both free and Open Source. Other great apps like Amazon Polly are X to Voice, Kokoro, Voice Engine and NaturalReader.