South Korean linguists are working to preserve endangered indigenous languages, choosing ones that have no written form. They create and teach a written version.

They don't use the Roman alphabet. Instead, they use the Korean script known as Hangeul.

Article here. The slide show and the video are also worth a look.

Instead, they use the Korean script known as Hangeul.

While the Korean writing system is one of the best in the world, it does however limit the accessiblity to outsiders, though if the language is moribund, it little matters. One can pretty much learn Hangeul in an afternoon. And the shapes of the glyphs gives a person some hints as to the manner of articulation of the sounds of the syllable.