Mapudungun, the language of the Mapuche of modern south-central Chile and southwestern Argentina, did not have a writing system when the Spanish arrived. There have been a number of proposals for orthographies or Mapudungun alphabets, all of them using Latin script, but no consensus has yet been achieved between authorities, linguists and Mapuche communities on the one to be used.
The main systems (in order of proposal) are the following:
Classic, used since 1890 by Rodolfo Lenz, Felix de Augusta y Wilhelm de Moesbach; among other corpora for the biographic narrations provided by Pascual Coña in 1926.
Alfabeto Mapuche Unificado ("Unified Alphabet"), used by Chilean and Mapuche linguists and used in most of the scientific literature about the language.
(*) Raguileo does not distinguish between /s/ and /ʃ/ or between /t̪/ and /t/. Also, Raguileo aims to use only one grapheme for each phoneme (no digraphs) so it uses some letters from the alphabet in an unexpected way. Wirizüŋun also does not distinguish between /s/ and /ʃ/.
(*) /ʈʂ/, which is spelled "tr" is also pronounced [tɻ].
Vowels
Mapudungun has six vowels. The three high vowels also have corresponding approximant consonants.