Most of the stuff I found was for Python 2.7! I&#x27;ll edit that into the post. My focus was for finding libraries that worked with new Python code, e.g. Python 3.5 code.<p>All of those libraries have Python 2.7 versions. Actually for all of them you pip install the same library; for pyttsx, `pip install pyttsx` and ignore jpercent&#x27;s update.<p>I&#x27;m not sure what you mean about pricing and testing for development. Are you referring to Google&#x27;s services? They offer 50 reqs&#x2F;day for voice recognition on a free developer API key (<a href="https:&#x2F;&#x2F;www.chromium.org&#x2F;developers&#x2F;how-tos&#x2F;api-keys" rel="nofollow">https:&#x2F;&#x2F;www.chromium.org&#x2F;developers&#x2F;how-tos&#x2F;api-keys</a>). Google Translate can also be used by gTTS; it will rate limit or block you if you send too many reqs&#x2F;min or per day without an appropriately registered API key, but you could play around with it for sure.<p>If voice recognition is important, it might be worth investigating Sphinx more and putting the time to tweak their English language model files. Synthesis is more difficult, though I think the Windows SAPI, OSX NSSS, and ESpeak on *nix are all &quot;good enough.&quot; There are also a range of commercial libraries.