OP2 (Oxford Parallel library for Unstructured mesh solvers) is a high-level embedded domain specific language (eDSL) for writing unstructured mesh algorithms with automatic parellelisation on multi-core and many-core architectures. The API is embedded in both C/C++ and Fortran.

The current OP2 eDSL supports generating code targeting multi-core CPUs with SIMD vectorisation and OpenMP threading, many-core GPUs with CUDA or OpenMP offloading, and distributed memory cluster variants of these using MPI. There is also experimental support for targeting a wider range of GPUs using SYCL and AMD HIP.

These pages provide detailed documentation on using OP2, including an installation guide, an overview of the C++ API, a walkthrough of the development of an example application, and developer documentation.


OP2 is released as an open-source project under the BSD 3-Clause License. See the LICENSE file for more information.


To cite OP2, please reference the following paper:

G. R. Mudalige, M. B. Giles, I. Reguly, C. Bertolli and P. H. J. Kelly, “OP2: An active library framework for solving unstructured mesh-based applications on multi-core and many-core architectures,” 2012 Innovative Parallel Computing (InPar), 2012, pp. 1-12, doi: 10.1109/InPar.2012.6339594.

  author={Mudalige, G.R. and Giles, M.B. and Reguly, I. and Bertolli, C. and Kelly, P.H.J},
  booktitle={2012 Innovative Parallel Computing (InPar)},
  title={OP2: An active library framework for solving unstructured mesh-based applications on multi-core and many-core architectures},


The preferred method of reporting bugs and issues with OPS is to submit an issue via the repository’s issue tracker. Users can also email the authors directly by contacting the OP-DSL team.


Development of the OP2 is or has been part supported by the Engineering and Physical Sciences Research Council (EPSRC) grants EP/1006079/1, EP/100677X/1 on Multi-layered Abstractions for PDEs, EP/JOl0553/1 Algorithms and Software for Emerging Architectures (ASEArch), EP/S005072/1 Strategic Partnership in Computational Science for Advanced Simulation and Modelling of Engineering Systems - ASiMoV, the Royal Society through their Industry Fellowship Scheme (INF/R1/180012), the UK Technology Strategy Board and Rolls-Royce plc. through the SILOET project, The Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences and the European Commission. We are also grateful for hardware resources during development from the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725, ARCHER and ARCHER2 UK National Supercomputing Service, the University of Oxford Advanced Research Computing (ARC) facility and hardware donations/access from Nvidia and Intel.