FDTDX vs OpenFOAM
FDTDX
fdtdx.readthedocs.io
OpenFOAM
openfoam.comSide by side
| Figure | FDTDX | OpenFOAM |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Physics Simulation Software | 8.6 (#12) | 8.7 (#5) |
| Data export | Yes | Yes |
| Delivery mode | desktop | desktop |
| Free plan | Yes | Yes |
| GPU support | The project describes GPU-accelerated simulations with multi-GPU scaling capabilities. | The v2606 release introduces GPU offloading as a compile-time option, while its GPU work remains on a separate development track. |
| Intended users | The project describes FDTDX as freely usable for research, development, and commercial work involving photonic nanostructures. | OpenCFD describes its services for science and engineering companies, consultancies, and universities. |
| Purpose | FDTDX is an open-source Python package for simulating and designing three-dimensional photonic nanostructures with the Finite-Difference Time-Domain method. | OpenFOAM is an open-source computational fluid dynamics toolbox for simulating fluid flow, heat transfer, and related physical processes. |
| Security | The repository page lists a Security and quality section but does not state a security certification or compliance standard. | OpenFOAM documentation states that user-supplied system calls are disabled unless allowSystemOperations is enabled, and warns that system calls carry potential security risk. |
| Support | The FAQ invites users to open GitHub discussions for unanswered questions and issues for suspected bugs, and says the maintainers regularly check discussions. | OpenCFD offers a one-year support package covering installation, bug fixes, updates, CFD assistance, and code customisation, with a maximum number of service hours per year. |
| 3D visuals | Yes | Yes |
Plans
In their own words
OpenFOAM
OpenFOAM is a free, open-source computational fluid dynamics toolbox for simulating fluid flow, heat transfer, and related physical processes. It provides pre-processing, mesh generation, solvers for different flow and physics problems, and post-processing tools. Built-in utilities include blockMesh and snappyHexMesh, and it can convert meshes from external formats. ParaView visualization is supported through the paraFoam launcher, reader modules, VTK conversion, and VTK output during simulations. OpenFOAM runs on Linux, macOS, and Windows, and supports self-hosted use. Its current release is v2606, released on 26 June 2026; GPU offloading is available as a compile-time option, with that work on a separate development track. It is distributed under the GNU General Public Licence. OpenCFD offers a one-year support package for installation, fixes, updates, CFD assistance, and code customization, subject to a yearly service-hours maximum. It does not respond to support queries without a prior package. Training courses are also offered, with prices provided through a schedule or enquiry process.