The Automated Similarity Judgment Program (ASJP) is a collaborative project applying computational approaches to comparative linguistics using a database of word lists. The database is open access and consists of 40-item basic-vocabulary lists for well over half of the world's languages. It is continuously being expanded. In addition to isolates and languages of demonstrated genealogical groups, the database includes pidgins, creoles, mixed languages, and constructed languages. Words of the database are transcribed into a simplified standard orthography (ASJPcode). The database has been used to estimate dates at which language families have diverged into daughter languages by a method related to but still different from , to determine the homeland (Urheimat) of a proto-language, to investigate sound symbolism, to evaluate different phylogenetic methods, and several other purposes.
ASJP was originally developed as a means for objectively evaluating the similarity of words with the same meaning from different languages, with the ultimate goal of classifying languages computationally, based on the lexical similarities observed. In the first ASJP paper two semantically identical words from compared languages were judged similar if they showed at least two identical sound segments. Similarity between the two languages was calculated as a percentage of the total number of words compared that were judged as similar. This method was applied to 100-item word lists for 250 languages from language families including Austroasiatic, Indo-European, Mayan, and Muskogean.
The ASJP Consortium, founded around 2008, came to involve around 25 professional linguists and other interested parties working as volunteer transcribers and/or extending aid to the project in other ways. The main driving force behind the founding of the consortium was Cecil H. Brown. Søren Wichmann is daily curator of the project. A third central member of the consortium is Eric W. Holman, who has created most of the software used in the project.