About IBM
IBM created Qiskit, the most widely used open-source software stack in quantum computing. In the Unitary Foundation's 2025 Quantum Open Source Software survey, 69% of respondents said they had used Qiskit in the past year.
Qiskit Aer is the ecosystem's high-performance simulator. Alongside exact statevector simulation it offers density matrix, unitary, stabilizer, extended stabilizer, and matrix product state (MPS) methods, so you can choose the right trade-off between exactness and scale for each circuit.
Aer's signature strength is realistic noise. Its noise model framework covers depolarizing, amplitude and phase damping, thermal relaxation, and readout errors, and it can generate device-calibrated noise models that mimic real IBM quantum hardware, so you see how a circuit degrades before spending a shot on a QPU.