The 0.26 version of OpenSesame for Mac is provided as a free download on our website. OpenSesame for Mac is included in Design & Photo Tools. The actual developer of this free Mac application is Sebastiaan Mathôt. The OpenSesame installer is commonly called opensesame_0.26-macos-2.zip. The most popular version of the software is 0.2. The unique identifier for this program's bundle is org.pythonmac.unspecified.opensesame.
From the developer:
OpenSesame is a graphical, open-source experiment builder for the social sciences. It sports a modern and intuitive user interface that allows you to build complex experiments with a minimum of effort. With OpenSesame you can create a wide range of experiments: Psychophysics, reaction time tasks, and questionnaires, to name but a few.
You may want to check out more software for Mac, such as Artboard coords, unrooted or Pyware 3D, which might be related to OpenSesame.