5.1 also introduced two important contributions from @mcditoos : Support for parity-dependent dynamics in the fermionic HEOM solver (which is needed for the correct reproduction of the Kondo peak in SIAM systems), and a new environment class!
The recent 5.1.0 release broadened the support for JAX across more solvers and utility functions in QuTiP thanks to the efforts of @AgarwalRochisha and Eric Giguère https://t.co/kuIVIN3rDt