DELTA (taxonomy)

DELTA (DEscription Language for TAxonomy) is a data format used in taxonomy for recording descriptions of living things. It is designed for computer processing, allowing the generation of identification keys, diagnosis, etc.^[1] It is widely accepted as a standard and many programs using this format are available for various taxonomic tasks.

It was devised by the CSIRO Australian Division of Entomology in 1971 to 2000, with a notable part taken by Dr. Michael J. Dallwitz. More recently, the Atlas of Living Australia (ALA) rewrote the DELTA software in Java so it can run in a Java environment and across multiple operating systems. The software package can now be found at and downloaded from the ALA site.^[2]

DELTA System

The DELTA System is a group of integrated programs that are built on the DELTA format. The main program is the DELTA Editor, which provides an interface for creating a matrix of characters for any number taxa. A whole suite of programs can be found and run from within the DELTA editor which allow for the output of an interactive identification key, called Intkey.^[3] Other powerful features include the output of natural language descriptions, full diagnoses, and differences among taxa.