The International Alphabet of Sanskrit Transliteration (I.A.S.T.) is a transliteration scheme that allows the lossless romanization of Indic scripts as employed by Sanskrit and related Indic languages. It is based on a scheme that emerged during the nineteenth century from suggestions by Charles Trevelyan, William Jones, Monier Monier-Williams and other scholars, and formalised by the Transliteration Committee of the Geneva Oriental Congress, in September 1894. IAST makes it possible for the reader to read the Indic text unambiguously, exactly as if it were in the original Indic script. It is this faithfulness to the original scripts that accounts for its continuing popularity amongst scholars.
University scholars commonly use IAST in publications that cite textual material in Sanskrit, Pāḷi and other classical Indian languages.
IAST is also used for major e-text repositories such as SARIT, Muktabodha, GRETIL, and sanskritdocuments.org.
The IAST scheme represents more than a century of scholarly usage in books and journals on classical Indian studies. By contrast, the ISO 15919 standard for transliterating Indic scripts emerged in 2001 from the standards and library worlds; it includes solutions to problems such as representing Old Indo-Aryan and New Indo-Aryan languages side by side in library catalogues, etc. For the most part, ISO 15919 follows the IAST scheme, departing from it only in minor ways (e.g., ṃ/ṁ and ṛ/r̥)—see comparison below.
The Indian National Library at Kolkata romanization, intended for the romanization of all Indic scripts, is an extension of IAST.