Thank you to all of the panelists for your introductions and initial comments. In my first posting, I suggested that we need better tools, better habits, better repositories, and higher expectations in order to achieve reproducibility. That seems like a useful way to structure the next few questions, so I will start with tools:
What currently-available tools do you recommend for enabling reproducible scientific computing? Is there a tool that we ought to have, but do not?
P.S. I am using "reproducibility" as an easy shorthand for re-usability, re-creation, verification, and related tasks that have already seen some discussion. Please interpret the question broadly.