|Preference||Name / link||OS||Licence||Price||Quality||Multilingual|
|1||eSpeak||Win Linux||GPL||free||poor||yes : 50+|
|2||MBrola||Win OSX Linux …||ok for redistribute||free||good||35+|
|3||Pico svox (VoxOoFox)||Win Linux OSX||open source||free||Good||EN ES FR IT DE|
|Microsoft Speech Platform||Win||OK for redistribute||free||good||26|
|Freeswitch||Linux Win OSX||Mozilla Public||free|
|FreeTTS||Linux Win32 OSX||BSD||free||EN|
|Festival||opensource X11||free||EN ES|
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|EN ES FR IT DE|
Comparison of speech synthesizers on wikipedia
eSpeak topped the ranking: GPL, many languages, multi OS. Its only flaw is its very low quality. In practice, this raises the problem of understanding. It still remains that we have to integrate default, it is the most universal.
Then comes MBrola, although it is not free software license, it is freely redistributable for non commercial projects, free, available in many languages and it is especially good in terms of understanding. We need to be able to use it.
Pico SVOX has the advantage of being open source, good quality and multi OS. But it is only available in a few languages.