Modalities
Software
Organisations tagged software: compilers, error correction, algorithms, and control stacks. Many also build hardware. 30 records use this tag. A company can carry more than one.
Vancouver, BC, Canada
Hardware-agnostic algorithms and quantum-inspired optimisation. Often cited as an early dedicated quantum software company. Spun out Good Chemistry.
Seattle, WA; Pasadena, CA (Caltech), United States
Company-asserted Ocelot (2025): ~90% QEC-overhead reduction claimed
Braket hosts IonQ, Rigetti, QuEra, IQM, OQC, and others. The internal Ocelot cat-qubit effort (2025) aims to cut error-correction overhead; a roughly 90% reduction is described as claimed.
Bengaluru (US ties), India
Quantum simulation for engineering, including CFD and CAE. Described as the first Indian startup in the IBM Quantum Network.
Tel Aviv, Israel
High-level quantum circuit synthesis for enterprise users in finance and pharma, with CUDA-Q integration. US commercial presence; some EU staff. Not a US-headquartered company.
Sydney, Australia
Reported Quokka emulates 30 qubits on classical hardware
Quantum education company and member of the Australian Quantum Software Network. Quokka is a 30-qubit emulator (Kickstarter; Good Design Award 2024). Not a quantum processor.
Singapore, Singapore
Quantum software, error mitigation, and algorithms, with CQT lineage. A Quantinuum startup partner. Collaborates with the Singapore Quantinuum centre.
Singapore and Dublin, Singapore
Hardware-agnostic software (Triple Alpha) that also owns and operates a quantum testbed. About US$120 million raised, cited in a government speech. First quantum software company described as owning a quantum computer in Singapore. Heavy hiring from CQT and NTU.
Karlsruhe / Munich, Germany
Chemistry and materials simulation software for industrial users.
Shenzhen, China
Software and simulators (HiQ historically; MindSpore Quantum / MindQuantum). No public hardware programme as of 2026. The public HiQ cloud domain was reported dead since about 2024. Open-source MindQuantum remains. Included so the directory does not imply an active Huawei processor.
Sydney, Australia
Quantum error correction, including a qLDPC architecture (Pinnacle) with a lower-overhead thesis versus the surface code. Seed of US$6 million led by LocalGlobe. Collaborations cited with PsiQuantum, Diraq, and IonQ.
Santa Rosa, CA; Quantum Benchmark was Kitchener, ON, United States
Owns Quantum Benchmark and the True-Q error-diagnostic software since 2021. Characterisation tooling, not a QPU vendor. Quantum Benchmark is no longer an independent Canadian company.
Busan, South Korea
IBM Quantum Network hub and hybrid cloud access for Korean enterprises, plus the KQC Qubiteer quantum-AI platform. Not an indigenous QPU maker at scale. The brief did not verify a major firm called QuantaLab.
Redmond, WA, United States
Contested claim Majorana 1 chip (Feb 2025) — not an independently verified logical-qubit demo
Azure Quantum resells IonQ, Quantinuum, Atom Computing, and others. Topological work was consolidated in the US after the Sydney closure in 2024. Majorana 1 was announced in February 2025; the brief says the claim is contested and is not yet a verified logical-qubit demonstration.
San Sebastián (Donostia), Spain
Quantum and quantum-inspired software, including tensor-network compression for AI. A Spanish government AI-sovereignty investment of about €107 million (SETT framing, 2026) was reported; the brief says to verify the instrument.
Santa Clara, CA, United States
Open-source hybrid quantum–classical SDK. CUDA-Q Logical, announced September 2026, targets fault-tolerant resource estimation. Integrates with Braket, Classiq, and others.
Innsbruck, Austria
Quantum architecture and the ParityOS compiler. Deep German and EU project footprint, including mobile quantum-computing work with Quantum Brilliance toward about 2027.
London / Bristol, United Kingdom
Near-term algorithms for materials and chemistry. $34 million Series B in September 2025. An ARPA-E catalyst award in June 2026.
Sydney; US offices in Los Angeles and San Francisco, Australia
Quantum control and error-suppression software (Boulder Opal, Fire Opal) plus Ironstone Opal navigation for GPS-denied settings. Series B expanded to US$113 million (about A$166 million) in October 2024, led by GP Bullhound. Member of the Australian Quantum Software Network.
Palo Alto / Bay Area, United States
Enterprise algorithms and quantum-inspired chemistry under the Promethium product name.
Tel Aviv, Israel
Error mitigation and suppression software, hardware-agnostic, with an IBM commercial partnership.
Ottawa, ON, Canada
QiSpace quantum-secure communications software that runs over classical networks.
Florianópolis (UFSC ecosystem), Brazil
Open-source Ket quantum programming platform, plus consulting and training. Reported to be developing an operating system for a CBPF superconducting effort. Listed as a QuIIN technology-association partner in secondary sources.
Montevideo, Uruguay
Quantum and hybrid optimisation for air and maritime cargo, grown from Universidad de Montevideo and the Airbus Quantum Computing Challenge. States membership in the IBM Quantum Network and the Microsoft Quantum Network. The brief calls this Uruguay’s quantum industry: one serious software company. Sotelo co-organised Quantum Hackathon Latam 2025.
São Carlos, Bauru, and São Paulo, Brazil
Quantum and quantum-inspired algorithms, optimisation, open-system dynamics, and training. Showcased in the ITU/TQI Quantum World Tour Brazil in November 2025. Part of a private sector the brief calls small and software-heavy.
Tokyo, Japan
Quantum chemistry software. Described as a leading Japanese software startup in a market otherwise dominated by conglomerates and national labs.
Cambridge; US foothold in Maryland, United Kingdom
Quantum error-correction stack (Deltaflow / Deltakit) and the QEC Report. A US headquarters in Maryland was announced in September 2026, with a Boston office. NQCC partner.
Palo Alto, CA, United States
Quantum and AI software, AQNav sensing, and post-quantum cryptography. Described as well funded.
Shenzhen, China
Algorithms, error correction, TensorCircuit, and quantum–AI research. The brief describes an active software and research effort with no public full-stack hardware, and collaborations with Peking University, USTC, and Origin cited in secondary sources.
Toronto, ON, Canada
Photonic computing and the PennyLane framework. CQCP recipient (up to CAD $23 million) and a federal CAD $195 million toward Project OPTIMISM manufacturing, inside a larger package of up to CAD $390 million announced March 2026. DARPA QBI Stage B. About $302 million gross from the SPAC.
Boston, MA, United States
Formerly Zapata Computing / Zapata AI. Hardware-agnostic applications and a 2026 agentic product called Quantum Pilot. Restructured in 2024–26; the brief says it is not the scale of the 2021 SPAC peak.