Richard Pittman was the editor of the 1st to 7th editions (1951- 1969).
Barbara Grimes was the editor of the 8th to 14th editions (1971- 2000). In 1971, information was expanded from primarily minority languages to encompass all known languages of the world. Between 1967 and 1973, Barbara completed an in-depth revision of the information on Africa, the Americas, the Pacific, and a few countries of Asia. During her years as editor, the number of identified languages grew from 4,493 to 6,809. The information recorded on each language expanded so that the published work more than tripled in size.
In 2000, Raymond Gordon Jr. became the third editor of the Ethnologue and produced the 15th edition (2005).
In 2005, Paul Lewis became the editor, responsible for general oversight and research policy, with Conrad Hurd as managing editor, responsible for operations and database management, and Raymond Gordon as senior research editor, leading a team of regional and language-family focused research editors.
In the Introduction of the 15th edition (2009), the Ethnologue defines a language as such: "How one chooses to define a language depends on the purposes one has in identifying that language as distinct from another. Some base their definition on purely linguistic grounds. Others recognize that social, cultural, or political factors must also be taken into account. In addition, speakers themselves often have their own perspectives on what makes a particular language uniquely theirs. Those are frequently related to issues of heritage and identity much more than to the linguistic features of the language(s) in question."
As explained in the introduction, one feature of the database since its inception in 1971 has been a system of three-letter language identifiers (for example “fra” for French), that were included in the publication itself from the 10th edition (1984) onwards.
At the invitation of the International Organization for Standardization (ISO) in 2002, SIL International prepared a new standard that reconciled the complete set of codes used in the Ethnologue with the codes already in use in the ISO 639-2 standard (1998), that identified only 400 languages, as well as codes developed by Linguist List to handle ancient and constructed languages. Published in 2007, the ISO 639-3 standard provided three-letter codes for identifying nearly 7,500 languages. SIL International was named the registration authority for the inventory of language identifiers, and administers the annual cycle for changes and updates.