Quanty is a scientific software project centered on a script language for formulating and solving quantum many-body problems. It helps researchers model interacting electrons and explore the behavior of complex materials by expressing problems in second quantization, while the software handles the underlying mathematics. Quanty can support quantum chemistry calculations as a post-Hartree–Fock tool and is also used in LDA++ approaches, including methods such as self-consistent field, configuration interaction, coupled cluster, and restricted active space.

Developed and maintained by Maurits W. Haverkort and collaborators, Quanty grew from work on core-level spectroscopy in correlated transition-metal and rare-earth compounds. Its most developed and documented applications include x-ray absorption and resonant diffraction, with examples also available across other fields. The software runs on Windows, Linux, and Mac, and can use all cores on a single computer for parallel jobs. Based on Lua, Quanty offers a flexible scripting environment that works on personal computers and supercomputers; users can run it without knowing Lua, while experienced users can access Lua’s extensions.