PyLith is an open-source finite-element code for dynamic and quasistatic simulations of crustal deformation, primarily earthquakes and volcanoes. Main page: [https://geodynamics.org/cig/software/pylith](https://geodynamics.org/cig/software/pylith) User Manual Binary packages Utility to build PyLith and all of its dependencies from source PyLith Wiki: [https://wiki.geodynamics.org/software:pylith:start](https://wiki.geodynamics.org/software:pylith:start) Archive of online tutorials Hints, tips, tricks, etc PyLith development plan Submit bug reports via https://github.com/geodynamics/pylith/issues Send all questions to: cig-short@geodynamics.org Features Quasi-static (implicit) and dynamic (explicit) time-stepping Cell types include triangles, quadrilaterals, hexahedra, and tetrahedra Linear elastic, linear and generalized Maxwell viscoelastic, power-law viscoelastic, and Drucker-Prager elastoplastic materials Infinitesimal and small strain elasticity formulations Fault interfaces using cohesive cells Prescribed slip with multiple, potentially overlapping earthquake ruptures and aseismic creep Spontaneous slip with slip-weakening friction and Dieterich rate- and state-friction fault constitutive models Time-dependent Dirichlet (displacement/velocity) boundary conditions Time-dependent Neumann (traction) boundary conditions Time-dependent point forces Absorbing boundary conditions Gravitational body forces VTK and HDF5/Xdmf output of solution, fault information, and state variables Templates for adding your own bulk rheologies, fault constitutive models, and interfacing with a custom seismic velocity model. User-friendly computation of static 3-D Green's functions Installation Detailed installation instructions for the binary packages are in the User Manual with detailed building instructions for a few platforms in the INSTALL file bundled with the PyLith Installer utility. We also offer a Docker image (https://wiki.geodynamics.org/software:pylith:docker) for running PyLith within a portable, virtual Linux environment. Release Notes Added --version command line argument to display version information for PyLith and its dependencies. Improved information displayed with the --help command line argument. Added --include-citations command line argument to display publications to cite when publishing results from computations using PyLith. General PyLith references are also displayed with the --version command line argument. Allow use of NetCDF versions greater than 4.1.3. Switch from using C++ API to C API. Fixed bug in Pythia associated with validation of parameters being done before help could be displayed. Fixed typos in manual for gravity and point forces. Added integration with Travis for automated testing.

{"references": ["Aagaard, B. T., M. G. Knepley, and C. A. Williams (2013), A domain decomposition approach to implementing fault slip in finite-element models of quasi-static and dynamic crustal deformation, Journal of Geophysical Research: Solid Earth, 118, 3059\u20133079, doi: 10.1002/jgrb.50217."]}

This project is supported by the U.S. Geological Survey Earthquake Hazards Program, GNS Sciences, and CIG. CIG is supported by the National Science Foundation award NSF-0949446.