  The goal of future quantum networks is to enable new internet applications
that are impossible to achieve using solely classical communication. Up to now,
demonstrations of quantum network applications and functionalities on quantum
processors have been performed in ad-hoc software that was specific to the
experimental setup, programmed to perform one single task (the application
experiment) directly into low-level control devices using expertise in
experimental physics. Here, we report on the design and implementation of the
first architecture capable of executing quantum network applications on quantum
processors in platform-independent high-level software. We demonstrate the
architecture's capability to execute applications in high-level software, by
implementing it as a quantum network operating system -- QNodeOS -- and
executing test programs including a delegated computation from a client to a
server on two quantum network nodes based on nitrogen-vacancy (NV) centers in
diamond. We show how our architecture allows us to maximize the use of quantum
network hardware, by multitasking different applications on a quantum network
for the first time. Our architecture can be used to execute programs on any
quantum processor platform corresponding to our system model, which we
illustrate by demonstrating an additional driver for QNodeOS for a trapped-ion
quantum network node based on a single $^{40}\text{Ca}^+$ atom. Our
architecture lays the groundwork for computer science research in the domain of
quantum network programming, and paves the way for the development of software
that can bring quantum network technology to society.
