Channelflow is a software system for dynamical-systems analysis of the incompressible Navier-Stokes equations for channel and plane Couette flow. Key algorithms include time integration, computation of steady states, traveling waves, and periodic orbits, linear stability analysis, analysis of symmetries, and state-space projections. The channelflow distribution includes about thirty command-line utilities for performing common calculations and a C++ library for writing short, high-level programs for the analysis of plane Couette and channel flows. Channelflow version 2.0 includes parallelization of time-stepping via MPI.