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The latest stable version is 3.3.9 Lentiform Loewenfeld, released on April 10, 2021 (release notes).
The standard download is based on Python 3.7 for 64 bit systems. The installer and
.zip packages are identical, except for the installation.
Some Python packages are not compatible with Python 3. If you want to use those, please download the Python 2.7 (64 bit) package below. Note: As of January 1, 2020, Python 2.7 is no longer maintained.
This article on the Mac OS support site explains how to override the security settings of Mac OS that will by default prevent OpenSesame from launching.
OpenSesame 3.3 is available through the Cogscinl PPA. Packages are developed and tested on Ubuntu 20.04 Focal Fossa. To add this repository to your software sources and install OpenSesame, run the following commands in a terminal:
sudo add-apt-repository ppa:smathot/cogscinl sudo apt update sudo apt install python3-opensesame
Some commonly used packages are not available through the PPA. You can install them through
pip install psychopy expyriment pyspellchecker fastnumbers js2py
First, create a new Python environment for OpenSesame (optional):
conda create -n opensesame-py3 python=3.7 # For Python 2: python=2.7.15 conda activate opensesame-py3
Next, add the relevant channels (
cogsci) and (
conda-forge) and install all relevant packages:
conda config --add channels cogsci --add channels conda-forge conda install python-opensesame opensesame-extension-osweb opensesame-plugin-psychopy psychopy rapunzel python-pygaze
Some packages are not available through conda. You can use
pip install for these.
pip install soundfile pygame yolk3k opensesame-extension-osf python-qtpip http://files.cogsci.nl/expyriment-0.10.0+opensesame2-py3-none-any.whl
Once you have installed all packages, you can simply run OpenSesame by (after having activated the correct environment) running:
Or for the Rapunzel code editor:
Older versions can be downloaded from GitHub releases:
The source code of OpenSesame is available on GitHub.
Which version of Python to use?
OpenSesame is currently built with Python 3.7.6 (standard package) and Python 2.7.15.
When (not) to update?
- Update while developing and testing your experiment; it is always best to use the latest version of OpenSesame.
- Do not update while running an experiment; that is, do not update while you are collecting data.
- Run an experiment with the same version of OpenSesame that you used for developing and testing.
Manually upgrading packages
- OpenSesame is a regular Python environment, and you can upgrade packages with
condaas described here:
Tips for system administrators
- When a new major version of OpenSesame is released (with a version ending in 0, e.g. 3.1.0), it is generally followed quickly by one or two maintenance releases (e.g. 3.1.1 and 3.1.2) that address major bugs. Therefore, if you are installing OpenSesame on systems that you do not update often, it is best to wait until the second or third maintenance release (e.g. 3.0.2, 3.1.3, etc.). That way you minimize the risk of rolling out a version of OpenSesame that contains major bugs.
- The Windows installer allows you to silently install OpenSesame using the