Concerto is an adaptive testing platform that allows users to create different kinds of online assessment, from simple surveys to complex IRT-based adaptive tests. It combines the flexibility of HTML presentation with the computing power of the R language, as well as the safety and performance of MySQL databases. It is open source and free for academic and commercial use. Concerto was developed by The Psychometrics Centre at the University of Cambridge.

Web: http://www.psychometrics.cam.ac.uk/page/338/concerto-testing-platform.htm