Abandoned projects

• libquantum - C library for quantum computing and quantum simulation.
• pQCS - Parallel quantum circuit synthesis with optimal T-count.
• BLACK-STONE - Specification and implementation of quantum common lisp, for gate-model quantum computers.
• goqu - Quantum computing simulation library for GoLang.
• libquantum - C library for quantum computing and quantum simulation.
• libQuantumJava - Crude translation from the C implementation of libquantum to a Java version.
• jquil - Java library for quantum programming using Quil.
• PyQLab - Library for instrument control and superconducting QIP experiments.
• PySimulator - Python with C++ backend simulator for superconducting circuits.
• QACG - Quantum Arithmetic Circuit Generator in Haskell.
• QCL - High level, hardware-agnostic programming language for quantum computers (syntax like C or Pascal).
• QCViewer - Visual quantum circuit design and simulation tool.
• QGL.jl - Performance orientated QGL compiler.
• Qlmp - Interpreter for the functional quantum programming language Qumin.
• Qiskit Aqua - Library of various quantum algorithm implemented with Qiskit.
• QOCS - Quantum OCaml Circuit Simulator is a functional approach to simulating quantum gates.
• QuantumUtils - Tools for quantum control, simulation, channel representation conversion, and perturbations.
• Quantum Virtual Machine - Reference implementation of Rigetti's Quantum Virtual Machine.
• Quince - Node-based GUI that allows for graphical configuration of qubit experiments in Auspex.
• Quipper - Scalable functional programming language for quantum computing based on Quantum Lambda Calculus.
• QuSim - Ideal noise-free multi-qubit simulator written in 150 lines of code.
• QSEL - Quantum programming language putting entanglement and superposition front and center.
• sapi_dimod - Dimod wrapper for D-Wave's Solver API (SAPI).
• Squankum - Visual Java quantum simulator.
• 8Q - 8 Qbit, Photonic Quantum Computer.

Experimental quantum computing

• Qlab.jl - Generic lab tools in Julia.
• Qlab - Measurement and control software for superconducting qubits.
• ARTIQ - Next-generation control system for quantum information experiments.
• OLSQ - OpenQASM package to perform optimal layout synthesis for quantum computing.
• MQT DASQA - Framework to encapsulate application-driven superconducting architecture design.
• MQT Qudits - A framework for research and education for mixed-dimensional qudit quantum computing available via the [mqt.qudits] Python package.
• pyEPR - Automated Python module for the design and quantization of Josephson quantum circuits.
• PyRPL - Turn your RedPitaya into a powerful DSP device, suitable as a digital lockbox and measurement device in quantum optics.
• QCoDeS - Python-based data acquisition framework for quantum experiments.
• QFlow-lite - Machine Learning tools for autotuning quantum dot experiments.
• QGL - Domain-specific language embedded in Python for specifying pulse sequences.
• Qiskit Metal - Quantum hardware design and analysis.
• QTT - Quantum Technology Toolbox is a framework for the tuning and calibration of quantum dots and spin qubits.
• Quantify - Data acquisition platform focused on Quantum Computing and solid-state physics experiments.
• qupulse - Quantum computing pulse parametrization and sequencing framework (formerly qc-toolkit).
• scqubits - Simulating superconducting qubits, obtaining energy spectra, plotting energy levels and more.
• Atomiq - Quantum hardware orchestration stack for complex quantum setups.

Quantum algorithms

• Tensorflow Quantum - Library for hybrid quantum-classical machine learning.
• XACC Examples - Example code using XACC for quantum computing.
• XACC QChem - QPU Benchmarks for Quantum Chemistry via XACC, Psi4 and OpenFermion.
• XACC VQE - Variational quantum eigensolver built on XACC for distributed, and shared memory systems.
• myQShor - Quantum implementation of Shor's algorithm.
• QuantumTomography.jl - Julia package to perform quantum state and process tomography.
• Adapt - Algorithms for adaptive refinement of measurements.
• Arline Quantum - Library with implementation of quantum gates and hardware, a part of Arline Benchmarks project.
• Boson Sampling - Library to calculate interferometer output probabilities given Fock state inputs to help better understand Aaronson-Arkhipov Boson Sampling arXiv:1011.3245 [quant-ph]
• FermiLib - Software for analyzing fermionic quantum simulation algorithms with ProjectQ.
• G/SG Morph - Quantum annealing algorithms for Graph/Subgraph Isomorphism based on Calude et al.'s paper "QUBO formulations for the graph isomorphism problem and related problems" 10.1016/j.tcs.2017.04.016
• MQT QAO - Automatic Framework for Solving Optimization Problems with Quantum Computers available via the mqt.qao Python package.
• MQT QUBOMaker - Automated QUBO formulation for optimization and pathfinding problems offering multiple encodings. Available via the mqt.qubomaker Python package.
• OpenFermion - Compiling and analyzing quantum algorithm for quantum chemistry simulations.
• OpenQAOA - Multi-backend SDK to create, customise and execute QAOA on NISQ devices and simulators.
• Paddle Quantum - Quantum machine learning platform to construct & train quantum neural networks, developed by Baidu.
• PyZFS - Package to compute zero-field-splitting tensors for molecules and spin quantum bits in semiconductors.
• QFog - Framework for analyzing both classical and quantum Bayesian Networks.
• QGrad - Library to integrate automatic differentiation tools such as JAX with QuTiP and related quantum software packages.
• Qiskit Nature - Quantum Chemistry including ground state, excited states and dipole moment calculations.
• QPanda - QPanda is a quantum computing framework that can be used to build, run, and optimize quantum algorithms.
• Qualtran - A library for expressing and analyzing Fault Tolerant Quantum algorithms.
• Quantum_Edward - Python tools for supervised learning by Quantum Neural Networks
• QuantumFlow - Quantum Algorithms Development Toolkit e.g. allowing for backpropagation with QAOA.
• Quantum TSP - Tutorials on solving Travelling Salesman Problem using quantum computing (QAOA).
• Qudit Team - Repository to extend Qiskit versatility to higher dimensional quantum states.
• ReCirq - Modules for running quantum computing applications and experiments through Cirq.
• spin_qudit_tomography - Code used in spin tomography using qudits.
• pyRiemann-qiskit - Library for machine learning and quantum programming based on pyRiemann and Qiskit projects.
• VQF - Implementation of Variational Quantum Factoring algorithm (in pyQuil)
• WebMark - Web platform for benchmarking quantum computing algorithms.
• Quantum Katas - Programming exercises for learning Q# and quantum computing.

Quantum Analog Hamiltonian

• Bloqade - Package for the quantum computation and quantum simulation based on the neutral-atom architecture.
• Pulser - Python library for pulse-level/analog control of neutral atom devices.

Quantum and post-quantum cryptography

• liboqs - C library for quantum-resistant cryptographic algorithms.
• openssh - OpenSSH with quantum-safe key exchange algorithms.
• openssl - OpenSSL with quantum-safe cryptographic algorithms.
• PQClean - Clean, portable, tested implementations of post-quantum cryptography.
• TQ42 Cryptography - Post-quantum algorithms, hash functions, digital signature, key encapsulation mechanism, PRNG, and key management functions.
• Crypto-Vinaigrette - Quantum-resistant asymmetric key generation tool for digital signatures.
• Qash-QKDC - Hashing algorithms/circuits powered by quantum operations.
• Qashchain - Quantum blockchain based on qash-qkdc circuits.

Quantum annealing

• C-to-D-Wave - Compile a very small subset of C to a D-Wave Hamiltonian function
• QA Prolog - Compile a subset of Prolog to a D-Wave Hamiltonian function
• QAOA.jl - Simulate quantum annealing and mean-field quantum annealing in Julia.
• chimera_embedding - Algorithms to generate native-structured embeddings for Chimera graphs.
• dimod - Shared API for Ising and QUBO problems.
• dwavebinarycsp - Map constraint satisfaction problems with binary variables to binary quadratic models.
• dwave-cloud-client - Min. implementation of the REST interface to communicate with D-Wave's Solver API.
• dwave_neal - Implementation of a simulated annealing sampler.
• dwave-system - API for easily incorporating D-Wave quantum annealers as samplers in the Ocean software stack.
• embedding_utilities - Mapping samples between original and embedded graph.
• micro_client_sapi_dimod - Dimod wrapper for the D-Wave Micro Client.
• minorminer - Heuristic tool for minor graph embedding.
• penaltymodel - Utilities and interfaces for using penalty models.
• qubovert - Formulating and simulated annealing of Ising, QUBO, and higher order problems with constraints.
• Qbsolv - QUBO solver with D-Wave or classical tabu solver backend.
• qubo-nn - Classifying, auto-encoding and reverse-engineering QUBO matrices. Also includes 20 problem formulations.
• dwave_networkx - Exploration and analysis of network graphs.
• qqa - GPU-parallel Quasi-Quantum Annealing toolkit for QUBO and Ising combinatorial optimisation, with PI-GNN / CPRA neural backends and a Simulated Annealing baseline, all under a single PyTorch API.

Quantum assembly

• Quil - Open hybrid quantum/classical instruction set currently used by Rigetti. Parser
• Blackbird - Open-source quantum instruction language currently used for Xanadu's photonic hardware.
• QMASM - Quantum macro assembler for D-Wave's quantum annealers.

Quantum compilers

• BQSKit - Berkeley Quantum Synthesis Toolkit is an optimizing quantum compiler and related tool-set.
• Catalyst - AOT/JIT compiler for hybrid quantum computing beyond NISQ. Written in MLIR. Python frontend via PennyLane.
• MQT SyReC - HDL-based synthesis of reversible circuits for optimized circuit designs.
• QCOR - C++ language extension and associated compiler implementation for hybrid quantum-classical programming.
• ScaffCC - Compilation, analysis and optimization framework for the Scaffold quantum programming language.
• TKET - C++ library for placement, routing, and optimization of quantum circuits (developed by Quantinuum).
• UniversalQCompiler - Synthesis of isometries (including unitaries and state preparation), channels and POVMs.
• QuantumCircuitOpt.jl - Julia package for provably optimal decompositions and compilations of quantum circuits
• Arline Benchmarks - Automated benchmarking platform for quantum compilers, quantum hardware and quantum algorithms.
• Mitiq - Cross-platform, quantum error mitigation toolkit and compiler from Unitary Foundation.
• MQT IonShuttler - Exact and heuristic scheduling to manage ion movement within trapped-ion hardware.
• NchooseK - Constraint-programming system that compiles to both circuit-model quantum computers and quantum annealers.
• QEDA - Quantum electronic design automation software for optical circuits using QASM.
• QGL2 Compiler - Language compiler for imperative Quantum Gate Language (QGL).
• Qiskit Terra - Python library for quantum circuit rewriting and optimization (supported by IBM).
• Qiskit ZX transpiler - Transpiler pass for Qiskit which uses ZX-calculus for circuit optimization.
• Qlasskit - Compiler from Python language to quantum circuits and binary quadratic models.
• Qubiter - Quantum compiler with Python wrapper for LAPACK's CS Decomposition to build a binary tree of matrices.
• SAT Circuits Engine - Qiskit-based high-level quantum circuits synthesis engine for n-SAT problems.
• UCC - Unitary Compiler Collection: frontend-agnostic open-source quantum compiler developed by Unitary Foundation.
• TKET2 - Rewrite based toolkit for optimization of quantum programs (version 2 of the TKET quantum compiler).
• EMRG - Quantum error mitigation toolkit with ZNE, PEC, and CDR support.
• CleitonForge - Differential fuzzer for quantum compilers and simulators (Rust + Python), with a shrinker and an exact-operator oracle.
• quilc - Rigetti's optimizing Quil compiler.

Quantum control

• C3 - Open-loop, closed-loop and automated Control, Calibration and Characterization of quantum devices.
• Krotov - Python implementation of Krotov's method for quantum optimal control.
• Quanlse - Quanlse provides quantum control solutions via a cloud SDK, developed by Baidu Quantum.
• gradpulse - Differentiable, multi-solver-validated pulse optimizer for open-system superconducting-gate fidelities.

Quantum converters

• qconvert-js - Quantastica's quantum programming language converter in Javascript.
• qconvert - Quantastica's quantum programming language converter in Python.
• qconvert - Quantastica's quantum programming language converter in Python.

Quantum data

• QDataSet - Quantum datasets for the training and development of QML algorithms.
• QuPrep - Classical-to-quantum data encoding and preprocessing library for quantum machine learning.

Quantum error correction

• Tesseract Decoder - Most Likely Error decoder designed for Low Density Parity Check (LDPC) quantum error-correcting codes.
• CodingTheory - Julia package for constructing and analyzing classical and quantum error-correcting codes.
• Chromobius - Python implementation of a "mobius decoder" for color codes used in quantum error correction.
• MQT QECC - Synthesis of fault-tolerant circuits. Decoders. Automatic Application of error correcting codes. Available via the mqt.qecc Python package.
• PyMatching - Python package for decoding quantum error correcting codes with minimum-weight perfect matching.
• qecsim - Python package for simulating quantum error correction using stabilizer codes.
• Qsurface - Python package for simulation and visualization of quantum error-correction on surface codes.
• autoq-qec - Multi-code fault-tolerant QEC resource estimator for arbitrary Qiskit circuits (Surface Code, Floquet Code, Bacon-Shor, Steane).

Quantum full-stack libraries

• Ket - Embedded programming language that introduces the ease of Python to quantum programming.
• Silq - Silq is a high-level quantum programming language with safe uncomputation and intuitive semantics.
• XACC - Extreme-scale programming model for quantum acceleration within high-performance computing (arXiv paper).
• avaloni - Programming language (interpreter) for classical-quantum hybrid computers.
• CUDA-Q - Platform for accelerated quantum-classical applications on GPUs, CPUs and QPUs.
• staq - Full stack quantum processing toolkit (arXiv paper).
• qpp - Quantum++ is a modern C++ general purpose quantum computing library, composed solely of template header files.
• bosonic-qiskit - Simulate hybrid boson-qubit systems within Qiskit, implemented as a part of the Co-design Center for Quantum Advantage (C2QA) of the National Quantum Initiative.
• Braket - Amazon's fully managed quantum computing service for building quantum algorithms.
• Cirq - Framework for creating, editing, and invoking Noisy Intermediate Scale Quantum (NISQ) circuits.
• Ocean - D-Wave System's suite of tools for solving hard problems with quantum computers.
• Perceval - Quandela's software library for programming realistic photonic quantum computers.
• ProjectQ - Hardware-agnostic framework with compiler and simulator with emulation capabilities.
• PyQudit - Python package for generalized and universal versions of quantum gates in N-dimensions.
• Qadence - Pasqal's package for building differentiable digital and digital-analog quantum programs realizable on neutral atom devices.
• Qibo - An open-source framework for quantum simulation, self-hosted quantum hardware control and calibration.
• quantum-os - Operating system based on Linux kernel for quantum computing.
• Strawberry Fields - Xanadu's software library for photonic quantum computing.
• Tangelo - Examples](https://github.com/goodchemistryco/Tangelo-Examples/) - Toolkit for quantum chemistry simulation workflows on quantum computers, maintained by SandboxAQ.
• TensorCircuit - Tensor network based quantum software framework for the NISQ era.
• pytket - Quantum computing toolkit for building, compiling, and executing quantum circuits (developed by Quantinuum).
• Q# - Microsoft's quantum programming language with Visual Studio integration.
• Qristal - Quantum Brilliance's hybrid quantum-classical C++/Python development platform (docs; core module).
• Qrisp - A high-level programming language and framework for creating and compiling quantum algorithms (GitHub).
• OpenQL - Compiler framework with algorithm libraries, optimizer, scheduler, QEC, mapping, micro-code generator.
• blueqat - Quantum computing SDK.
• Qiskit - SDK for working with quantum computers at the level of extended quantum circuits, operators, and primitives. (supported by IBM).
• Tequila - Extensible Quantum Information and Learning Architecture developed by Alan Aspuru-Guzik's group (UofT).
• Forest - Rigetti's software library for writing, simulating, compiling and executing quantum programs.
• QCaml - Lightweight OCaml library to experiment with quantum states, gates and measurements.
• hybridlane - Full-stack library for mixed-variable (CV-DV) quantum programming across simulators and hardware within PennyLane.
• LIFT - Unified compiler framework for AI and quantum computing: a single SSA intermediate representation for tensor ops, quantum gates, and classical-quantum hybrids, with 13 optimisation passes, O0-O3 pipelines, noise-aware scheduling, cost modelling, and LLVM IR / ONNX / OpenQASM 3.0 backends. Published on crates.io (docs).

Quantum fun

• Entanglion - The world’s first open source quantum computing board game. For 2 players.
• Unitary - API library providing common operations for adding quantum behaviors to games.
• Quandoom - Port of DOOM for a quantum computer.
• Quantum Puzzle Generator - Educational puzzle game for Android and iOS.
• bloqit - Tiny qubit duel for your smart phone.
• QiskitBlocks - Game that teaches quantum computing using Qiskit in a Minetest block world.
• Quantum Awesomeness - Simple puzzles to benchmark various quantum processor.
• Quantum Battleships - Playing battleships with quantum measurements.
• Quantum Catsweeper - Quantum game loosely based on Minesweeper Flag.
• SudoQ - Sudoku solver that leverages a D-Wave Quantum Annealer.
• Quantum Music Composer for IBM Q - Compose and perform quantum music with IBM Q.
• Quantum Music Composer for Rigetti - Compose and perform quantum music with Rigetti's Forest.
• Quantum Game with Photons - Puzzle game in browser, with polarization, superposition, and measurement.
• feyn - Puzzle game for the browser in which you need to find the combination of gates that the qubits need to pass.
• Quantum Nematode - C. elegans navigation simulation using quantum variational circuits.

Quantum interoperability

• Digital Soul - Unified platform for CPU, GPU, FPGA, and Quantum Computing.
• scikit-quant - This is a package to improve interoperability between different quantum computer software packages.

Quantum simulators

• Quantum JavaScript (Q.js) - Drag-and-drop circuit editor, simulator, documented API, text-as-circuit DSL, concept primers.
• QuantumOptics.jl - Numerical framework to simulate various kinds of open quantum systems in Julia.
• QuaC - Parallel time-dependent open quantum systems solver.
• TNQVM - Tensor Network QPU Simulator for Eclipse XACC.