Uyghur alphabets
Uyghur is a Turkic language with a long literary tradition spoken in Xinjiang, China by the Uyghurs. Today, the Uyghur Arabic alphabet is the official writing system used for Uyghur in Xinjiang, but other alphabets - the Ughur Latin and Uyghur Cyrillic alphabets - are still in use, especially outside Xinjiang.
History
Old Uyghur and Modern Uyghur
The Old Uyghur language and Modern Uyghur are distinct Turkic languages and are not different stages of the same language. The Old Uyghur language is ancestral to Western Yugur, while modern Uyghur is descended from one of the Karluk languages.
Old Uyghur alphabets
5th to 18th century
In the 5th century Old Uyghur was written for the first time using the Sogdian alphabet. This fell out of use during the 10th century, when it evolved into the Old Uyghur alphabet, although it was taken into use again between the 15th and 16th century. While the Sogdian alphabet was still in use, it was written with the Old Turkic alphabet from the 6th-9th centuries.