This program should convert CASTEP's .check, .castep_bin, orbitals and .cell to various other formats, particularly so that they can be visualised with Jmol, XCrysDen, gnuplot and other programs. It can extract charge and spin densities, wavefunctions, symmetry operations, and much else besides. It also interfaces with Abinit, Quantum Espresso, Siesta, VASP, and other electronic structure codes.

The code can also manipulate .cell and .pdb files, building supercells, performing shifts, adding vacuum and rolling nanotubes.