sable is an xml markup language used to annotate texts for speech synthesis. it defines tags that control how written words, numbers, and sentences are audibly reproduced by a computer. sable was developed as an informal joint project between sun microsystems, at&t, bell labs, and the university of edinburgh (the initial letters of each make the word "sable") as an initiative to combine three previous speech synthesis markup languages ssml, stml, and jsml.