Identification of specimens (either extant or fossil) is a crucial point for any study in biology: inventory of biodiversity, phylogenetic studies, ecology etc. During most of the last two centuries printed dichotomous keys have been the main tool for practical identification. The knowledge representation and computing capabilities available nowadays and the common use of microcomputers has suddenly opened new perspectives.

Biologists began producing computer-aided-identification systems in the late 1960s. The main difference between classical keys and these systems is the replacement of fixed sequences of questions on a printed key by a dynamic free multi-access system including images and documents to help the user.

Xper2 and its associated tools is a plate-form dedicated to taxonomic descriptions and computer-aided-identification. It is quite comparable with other existing software like those developed on DELTA format. It includes an editor to edit taxonomic standardized descriptions and several functionalities to identify specimens, to compare and compute morphological dissimilarities, to import or export data from/to other formats etc.

This program is free. However, it is not open source. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Unported License (link is external).

Xper2 is a free access software available on Windows, MacOS or Linux.

It requires no special computer skills. It is very easy to use for the amateur naturalist that wants to identify a specimen with an already made application, as well as for the professional taxonomist that creates new applications.

Computer-Aided Identification is available on line and locally.

Xper2 development benefits from previous experience of the LIS (with Xper software), Xper2 is able to import applications stored in the old Xper format.

Knowledge bases on various taxonomic groups are avalaible on line. Xper2 is mainly based on the research of J. Lebbe, R. Vignes