I need a source for a TTS engine.
I also want a source of voice vocabularies, a large amount of voice vocabularies would be more useful actually.
I know of the Microsoft solutions, and also the extended voices they sell for $295. Fishing for others.
Liberal licensing would be nice. Having to pay for it is not a problem if it is really that good and can be liberally used after purchase.
Cross-platform is a plus. TTS domain specific support is a plus. Big plus if it's pay once to use liberally, but that's unlikely.
Exposed interface for browsers is a plus.