While working on a project every member of the team can add his libraries, extensions and setup the project as he sees fit.
The problem arises when that process needs to be repeated with other members of the team.
Vagrant, one of the many tools that you might have heard of but did not have a chance to look at, is used to simplify the development setup and allowing identical setup to all the memebers of the team. During the talk I will try to explain why you should use Vagrant/Puppet and what are the advantages/disadvantages