From OpenCog

The virtual machine created has all the dependencies required for working on cogutils, atomspace, moses, and opencog.

If you are new to vagrant, see https://www.vagrantup.com/docs/why-vagrant/ or https://www.vagrantup.com/docs/getting-started/ if you like to understand what vagrant is. Understanding the working of vagrant is not required for contributing to opencog.

The common steps after installing VirtualBox, git and Vagrant for your os and running a bash(on windows use the equivalent powershell commands) shell are:

mkdir opencog_repos
cd opencog_repos
git clone https://github.com/opencog/opencog

# You can clone other repos if you so choose

ln -s $PWD/opencog/lib/Vagrantfile Vagrantfile
vagrant up
vagrant ssh

# The folder from which your run 'vagrant up' is accessiable at
# '/home/vagrant/opencog' on sshing into the virtual machine.

# Do your thing

vagrant halt

This is for having a common updated wiki entry for running vagrant.