IBM Expands Qiskit Beyond Python with Native C API Bindings for Fortran, C++, and Julia

IBM Quantum has released details on the expansion of its open-source software stack, introducing native C API bindings (qiskit.h) that connect the core Rust data model of Qiskit v2.0 directly to the primary programming languages of high-performance computing (HPC): Fortran, C++, and Julia. While Python remains the standard entry point for quantum software development, classical supercomputing simulation codes in chemistry, physics, and material science rely heavily on compiled languages. By exposing a unified C interface to Qiskit’s Rust core, IBM enables researchers to construct, transpile, and execute quantum circuits natively within classical HPC application suites without calling an intermediate Python interpreter or incurring Global Interpreter Lock (GIL) performance overhead. [ Summary of Qiskit Native Language Bindings ]Language BindingIntegration MechanismHPC Workflows & Target Ecosystems• qiskit-fortran• Standard foreign-function interface (iso_c_binding)• Direct memory pointer passing for quantum chemistry codes (GAMESS, Quantum ESPRESSO, CP2K, VASP) and nuclear physics tools (BIGSTICK).• qiskit-cpp• Header-only library linked to Qiskit C shared library• High-performance physics simulation frameworks (LAMMPS, GROMACS) and exascale GPU acceleration layers (CUDA, Kokkos).• Qiskit.jl• Julia wrapper for Qiskit C API & QiskitIBMRuntime.jl• Interactive, dynamic scientific workflows integrating classical ODE solvers (DifferentialEquations.jl) and tensor network simulators (ITensors.jl). Because all three language bindings interface directly with the same underlying Qiskit shared library, they are fully interoperable. A quantum circuit constructed in a Fortran linear algebra routine can be passed directly to a C++ execution module or a Julia post-processing pipeline without data conversion. The native bindings support tightly coupled quantum-centric supercomputing (QCSC) workflows, such as Hamiltonian simulation, variational optimization, and dynamic time-evolution via Trotterization. By embedding quantum circuit calls as linked subroutines within classical C++, Fortran, or Julia code bases, researchers can execute hybrid algorithms on quantum hardware while retaining classical memory structures and native compiler optimizations. Review the technical announcement on the IBM Quantum Blog here and inspect the developer documentation for the Qiskit C API here. In GQI Portal The players behind the news The team that writes QCR tracks every company, deal and technology in the GQI Factory, GQI's verified database of the quantum industry. Next up: every story linked to its players, coming to QCR's paid plans. Players →Companies and institutions across the quantum industry, by segment. Scorecards →How the players compare on hardware, software, funding and more. Newsletter QCR Alerts in your inbox The latest reporting and analysis from Quantum Computing Report. Free, unsubscribe any time. Sign up for QCR Alerts Leave a commentCancel replyAll fields are required. Your email address will not be published.CommentName Email Type in the text displayed above Δ