Open source, GPL license.
Written in python (and a bit of C++), supports Linux, Windows, macOS/OSX.
Support of most VASP file formats and .xyz format.
Displays structure, unitcell, supercell, charge/probability/spin density, local potential, forces, velocities, dynamics, measure distances and angles.
Simple structure editor, supports both Cartesian and direct coordinates. Building of supercells and crystal surfaces via cell replication.
Analyze electronic properties, total and local DOS and band structure.
Simulation of STM images (constant current and constant height).
Brillouin zone and K-points visualization.
Inspection of convergence - size of free energy and selected forces along relaxation path.
Phonon properties - dispersion, velocity autocorrelation.
Interactive plots and 3D displays with export to various formats.
Database support.