| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 1 |
| Spec score · Physics Simulation Software | 8.6 (#12) | 7.7 (#46) |
| Assessment tools | No | No |
| Authoring tools | Yes | No |
| Delivery mode | desktop | desktop |
| Free plan | Yes | Yes |
| Installation | The maker provides a pip installation command and an editable installation path for development. | Installation requires the Rust toolchain; Python 3.6+ and listed Python libraries are optional for helper scripts and input-file manipulation. |
| Lesson library | No | No |
| Limitations | The FAQ describes FDTDX as relatively new and says bugs may occur despite testing. | RustBCA models materials as amorphous and static, so it cannot capture ion channeling or temperature effects, and BCA does not directly simulate multi-body effects or chemical sputtering. |
| Purpose | FDTDX is an open-source Python package for simulating and designing three-dimensional photonic nanostructures with the Finite-Difference Time-Domain method. | RustBCA is a general-purpose code for simulating ion–material interactions, including sputtering, reflection, and implantation, using the binary collision approximation. |