Yambo
A many-body electronic-structure code for excited-state materials properties, including GW, Bethe–Salpeter and nonequilibrium Green-function methods.
Where it fits
Quasiparticle energies, excitonic optical spectra and electron–phonon effects.
Limits and practical considerations
Requires ground-state data from a compatible DFT code; many-body convergence can be costly.
Licensing and access
Open source under GPL; the upstream DFT program and its datasets have separate terms.
Official documentation and project