Speech Synthesis Markup Language

'Speech Synthesis Markup Language (SSML) is a markup language used to give instructions to speech synthesizers on what to say and how to say it. It is used by Amazon for its Alexa products and services, but it is a W3C recommendation that people of various companies have worked on, so it is nonproprietary.

Specs

 * Official W3C SSML 1.1 Recommendation

Links

 * Amazon SSML Reference