SimFlow vs Step

SimFlow is desktop software for computational fluid dynamics, covering the workflow from mesh generation through post-processing. Simulations stay on the user's hardware, and the software runs on Windows, Linux, and macOS, including Apple Silicon. Jobs can run on a local cluster, remote server, or cloud, with HPC-grade parallel computing and no per-core or hourly charges. The full simulation engine is included in every plan. CAD imports include STL, STEP, IGES, OBJ, and BRep; results can be exported in VTK, Fluent, Tecplot, and Ensight formats. SimFlow integrates with ParaView, OpenFOAM, Docker, and Windows Subsystem for Linux. The free plan has no signup, credit-card requirement, or time limit, but is limited to 200,000 mesh nodes and one CPU. Professional costs €8,000 per year; Enterprise costs €10,000 per year. Commercial plans include a 30-day trial. Perpetual licenses are also available, with one year of maintenance and optional yearly renewals.

Step is a free Linux desktop application for exploring physical systems through interactive simulations. Users can change body and force properties while a simulation runs. Supported models include two-dimensional classical mechanics, molecular dynamics, sound waves, and deformable bodies, with particles, damped springs, gravitational and Coulomb forces, rigid bodies, and collision handling. Step calculates unit conversions, expressions, error propagation, and solver error estimates. Explicit and implicit solvers reach 8th order, with optional adaptive timesteps; most require GSL. Graph, meter, and tracer tools visualize results, while a controller changes properties using keyboard shortcuts. Tutorials, example experiments, object information, and an integrated Wikipedia browser provide learning material. More examples can be downloaded through KNewStuff. Expression calculations such as unit conversion require libqalculate. Step is GPL-2.0+ software, and its StepCore library can be used separately. The listed release is Step 26.08.2, released 2026-10-08.