The goal of MDAnalysis is to make it easy for users to analyze data that are produced by simulations (primarily molecular dynamics simulations) that run on some of the largest supercomputers in the world. MDAnalysis accomplishes this goal by providing a toolkit of programming building blocks that provide an abstract Python interface to the simulation data — agnostic of the specific simulation package that produced it — that lends itself to interactive data exploration and rapid prototyping but is also a robust foundational library that can form the basis for new computational tools.