There are four Kartvelian languages (ქართველური ენები) - Georgian, Svan, Mingrelian and Laz - which together form a language isolate, like Basque - of unknown origin, and unrelated to any other language group, including Indo-European. Laz is by far the most endangered today. 1/2 
Most Laz speakers actually live in Turkey, not Georgia. This collection of Laz texts and folklore - published in Laz with a side-by-side Georgian translation - was gathered from residents of the village of Sarpi (the only Laz village remaining on Georgian territory) in 2005. 2/2
Laz has no official status in either Turkey or Georgia, and no written standard. It's used only for familiar and casual speech; for literary and business purposes, Laz speakers use their country's official language (Turkish or Georgian). There are around 20 000 native speakers.
The most differentiated of the four Kartvelian or South-Caucasian languages is Svan, which is thought to have split off from Proto-Kartvelian in the 2nd millennium BC or earlier, about one thousand years before Georgian did. It retains archaic features not present in Georgian.
The first ABC and primer in the Svan language was 'Lushnu Anban' [Лушну Анбан] published by the Society for the Reestablishment of Orthodox Christianity in Tbilisi in 1864.
This Svan ABC contains spelling exercises, prayers, a catechism, and a trilingual glossary (Svan-Georgian-Russian). The alphabet was based on Cyrillics and brief explanations were written in Russian, an editorial choice which was met with hostility and sharply criticized.
Svan is spoken by 30000 people in the north west of Georgia in Svaneti. There are also several thousand Svan speakers in Kodori Valley in the Republic of Abkhazia, an entity which considers itself an independent country but which is considered part of Georgia by the Georgian gov.
Like Laz, Svan is a severely endangered language. It has no official status in Georgia and there is no standard written form. When it is written, a version of the Georgian alphabet is usually used, though the Cyrillic and Latin alphabets are also used occasionally.
