What is Deltaflow.OS®?

Deltaflow.OS® is a radically new operating system for quantum computers. Quantum computers contain classical and quantum computing elements which must be orchestrated to tease out optimal performance. This is crucial for near-term applications such as quantum chemistry. In the long term, quantum error correction requires close integration of quantum and classical compute.

How does Deltaflow.OS® work?

Inspired by heterogeneous architectures, Deltaflow.OS® makes all computing elements in the stack accessible – CPU, FPGAs and qubits. This empowers the quantum programmer to implement fast operations at the right level in the stack, increasing performance compared to other systems such as the circuit model of quantum computing, which hides the stack in a black box.

Why use Deltaflow.OS®?

Low latency

With Deltaflow.OS® you can leverage the full capabilities of your hardware: no bulky software to slow you down. The extra performance that you gain will shorten your path to quantum advantage.

Accelerated R&D

Deltaflow.OS® professionalises the tool chains you use, providing debugging and emulation tools. It allows you to get gateware onto FPGAs with ease.

Full stack

Deltaflow.OS® connects applications with the control stack. We provide a framework for users to interact with all layers in the stack, enabling the development of functions from algorithms to qubit tune-up.



A hosted programming language, Deltalanguage allows the programmer to define a graph of all the compute elements and declare the transport of data between them. Depending on which type of hardware a part of the program is running on, the nodes of this graph get filled with python (for the CPU) or migen (for the FPGAs). A hardware abstraction layer is built into the language, that standardises which operations can be triggered on qubits. This makes Deltaflow.OS® portable across technologies.


Our runtime takes care of executing Deltaflow® programs, scheduling and system services. Its networking and communication abstractions allow you to create communication channels on clusters of FPGAs. The Deltaflow® language and runtime form an operating system which we can install in your lab. Alongside the OS, we build emulators of the control stack that facilitate debugging and continuous integration.


Riverlane’s application library in Deltaflow.OS® is called Anian®, after a semi-mythical strait believed to give access to the Arctic Northwest Passage. Anian® provides quantum chemistry applications. Driven by the needs of end-users, Anian® includes our patented algorithms that decrease quantum hardware requirements, such as the accelerated Variational Quantum Eigensolver. It includes different ansätze, measurement strategies, noise models and algorithms.

Try out Deltaflow-on-ARTIQ


We have a grand vision: an operating system that makes quantum software portable across qubit technologies; that is scalable to millions of qubits; and, that teases the highest possible performance out of every qubit – even for applications like error correction that need fast feedback loops. Deltaflow-on-ARTIQ is our first step towards achieving this vision. It consists of:

  • The Deltaflow language which lets you define a graph of nodes representing the different elements of compute and the wires between them.
  • The Deltasimulator which lets the user test programs on simulated hardware.
  • Deltamodels which connect the Deltasimulator to an emulator of the ARTIQ control system. You can run Deltaflow programs on this ARTIQ backend. Note that the stand-alone emulator is currently available to beta-testers only, please contact us if you’d like to try it.

This version of Deltaflow-on-ARTIQ is freely available and can be accessed here.

We would love feedback through our survey.

Please contact us at if you need support, would like access to the stand-alone ARTIQ emulator, or would like to discuss Deltaflow-related projects.