The qutip-qip package used to be a module qutip.qip under QuTiP
(Quantum Toolbox in Python). From QuTiP 5.0, the community has decided
to decrease the size of the core QuTiP package by reducing the
external dependencies, in order to simplify maintenance. Hence a few
modules are separated from the core QuTiP and will become QuTiP family
packages. They are still maintained by the QuTiP team but hosted under
different repositories in the QuTiP organization.

The qutip-qip package, QuTiP quantum information processing, aims at
providing basic tools for quantum computing simulation both for simple
quantum algorithm design and for experimental realization. Compared to
other libraries for quantum information processing, qutip-qip puts
additional emphasis on the physics layer and the interaction with the
QuTiP package. The package offers two different approaches for
simulating quantum circuits, one with QubitCircuit calculating unitary
evolution under quantum gates by matrix product, another called
Processor using open system solvers in QuTiP to simulate noisy quantum
device.