The current stable version is 2.1.2b.
Please visit psiturk.org for more information.
You are welcome to use this code for personal or academic uses. If you fork, or use this in an academic paper please cite as follows:
McDonnell, J.V., Martin, J.B., Markant, D.B., Coenen, A., Rich, A.S., and Gureckis, T.M. (2012). psiTurk (Version 1.02) [Software]. New York, NY: New York University. Available from https://github.com/NYUCCL/psiTurk