The five general-purpose SDKs, by GitHub stars
These are the frameworks people build circuits in day to day.
- →Qiskit : 7,669 stars, IBM's SDK and the largest ecosystem in the field
- →Cirq : 5,033 stars, Google's NISQ-focused framework
- →PennyLane : 3,385 stars, Xanadu's differentiable-circuit and QML framework
- →pyQuil (Rigetti Forest SDK) : 1,494 stars, the original quantum programming SDK, predating Qiskit
- →NVIDIA CUDA-Q : 1,102 stars, GPU-accelerated circuit simulation and hybrid quantum-classical kernels
- →Amazon Braket SDK : 371 stars, the client library for AWS's multi-vendor hardware broker
Qiskit's lead reflects IBM's multi-year head start and its tie to free real quantum hardware access. Choose the SDK based on your own project's needs rather than the star count alone.
Domain-specific and research libraries
Beyond the general SDKs, a second tier of libraries covers specialized use cases.
- →OpenFermion : 1,719 stars, Google's library for quantum chemistry and fermionic simulation
- →OpenQASM : 1,495 stars, the interchange language specification most SDKs compile down to
- →ProjectQ : 976 stars, an early ETH Zurich framework, still cited often though development has cooled
- →Strawberry Fields : 854 stars, Xanadu's photonic quantum computing framework, last updated in January 2026
Strawberry Fields and ProjectQ have been around for years, and their commit activity has slowed noticeably next to the actively developed SDKs above. Worth knowing before you build something long-lived on either, though both remain good references.
Simulators built for raw speed
Before quantum hardware, there were CPUs and GPUs. When the bottleneck is compute rather than qubit access, these are the projects worth reaching for.
Error correction, mitigation, and circuit optimization
Fault tolerance research has its own toolchain, distinct from the general SDKs, and it is where some of the most technically important open source work in the field happens.
- →Stim : 797 stars, Google's stabilizer-circuit simulator built for surface-code-scale experiments
- →Mitiq : 441 stars, the Unitary Foundation's framework-agnostic error mitigation toolkit
- →Qualtran : 373 stars, Google's library for costing out fault-tolerant algorithms in qubits and T gates
- →PyMatching : 357 stars, a fast minimum-weight matching decoder for surface codes
- →BQSKit : 186 stars, Berkeley Lab's numerical circuit synthesis and optimization compiler
PyMatching's commit pace has slowed over the last few months relative to the others in this group, worth knowing if you're picking a decoder to depend on long-term.
Educational repos and awesome lists: check the commit date before you trust the star count
- →awesome-quantum-computing : 3,241 stars, a widely bookmarked curated list, though its last real update was July 2024
- →Microsoft QuantumKatas : 4,904 stars, self-checking Q# programming exercises, though the repository has had no meaningful commits since August 2024
- →awesome-quantum-software : 2,307 stars, a comparable curated list that is still actively updated
- →Qiskit Textbook : 1,030 stars, the original interactive Qiskit textbook repository, though IBM Quantum Learning is the better resource today
Two of the most-starred repositories in this entire list, QuantumKatas and awesome-quantum-computing, remain worth bookmarking as starting points for newcomers, even though neither has seen a meaningful commit in about two years. The star count reflects how many people found them valuable in the past, not whether they're maintained today.
Frequently Asked Questions
What is the most popular quantum computing project on GitHub in 2026?
By GitHub stars, IBM's Qiskit leads every other general-purpose SDK, with roughly 2,600 more stars than Cirq, the next closest. That reflects years of investment and its direct tie to free real quantum hardware, not necessarily that it is the right choice for every project.
Does a high star count mean a project is well maintained?
No, and two of the most-starred repositories on this list prove it directly: Microsoft's QuantumKatas (4,904 stars) and awesome-quantum-computing (3,241 stars) have both had no meaningful commits in roughly two years. Always check the last commit date on a repository before depending on it, not only the star count.
How often is this ranking updated?
The star counts and commit dates here were checked directly against the GitHub API on August 4, 2026. They will drift as the year goes on, faster for the most popular projects. Follow the linked repository directly if you need the current number.