zbMATH Open (formerly known as Zentralblatt MATH) is the world's most comprehensive and longest-running abstracting and reviewing service in pure and applied mathematics. It is edited by the European Mathematical Society (EMS), the Heidelberg Academy of Sciences and Humanities, and FIZ Karlsruhe. zbMATH Open provides easy access to bibliographic data, reviews and abstracts from all areas of pure mathematics as well as applications, in particular to natural sciences, computer science, economics and engineering. It also covers history and philosophy of mathematics and university education. All entries are classified according to the Mathematics Subject Classification Scheme and are equipped with keywords in order to characterize their particular content. Coverage starts in 1826 and is complete from 1868 to the present by the integration of the “Jahrbuch über die Fortschritte der Mathematik” database.