CfdOF — The Complete Guide: OpenFOAM Simulations Inside FreeCAD with a Graphical Interface
CfdOF is a free FreeCAD workbench that sets up, meshes and runs OpenFOAM flow simulations from a GUI: boundaries, physics and mesh, no hand-edited case files.
Guides and Articles
CNCjs — The Complete Guide: Controlling a CNC Machine from Your Browser
CNCjs is an open-source, browser-based CNC controller for Grbl, Marlin, Smoothieware and TinyG machines, with a 3D toolpath view. Runs on a Raspberry Pi.
LaserGRBL — The Complete Guide: Laser Engraving and Cutting on GRBL Machines
LaserGRBL is free, open-source software for GRBL laser machines: it turns images and SVG files into G-code, sets power and speed, and streams the job.
NanoVNA-Saver — The Complete Guide: Measuring Antennas, Filters and Cables with a NanoVNA
NanoVNA-Saver is free desktop software for low-cost NanoVNA analysers: frequency sweeps, Smith charts, VSWR and TDR for tuning antennas and checking cables.
QucsStudio — The Complete Guide: Circuit and RF Simulation, Free Even for Commercial Use
QucsStudio is a Windows circuit and RF simulator: DC, AC, transient, S-parameters, harmonic balance, microstrip tools and filter synthesis. Free for any use.
GNU Radio — The Complete Guide: Signal Processing and Software-Defined Radio in Blocks
GNU Radio is an open-source toolkit for signal processing and software-defined radio: chain filters, modulators and FFTs in a graphical editor, then run live.
OpenDSS — The Complete Guide: Distribution Grid Simulation and Renewable Integration
EPRI’s OpenDSS simulates distribution grids: power flow, harmonics, faults and time-series runs to test how much solar, storage and EV charging a feeder takes.
HYSPLIT — The Complete Guide: Free Air Trajectories and Dispersion of Pollutants, Smoke and Ash
HYSPLIT is a free NOAA model for air trajectories and the dispersion and deposition of pollutants, smoke, ash and radionuclides, from global weather data.
AERMOD — The Complete Guide: Free Air Dispersion Modelling for Stacks and Area Sources
AERMOD is a free US EPA air dispersion model: ground-level concentrations around stacks and industrial plants, for environmental impact studies and permit work.
WASP — The Complete Guide: Free Water-Quality Modelling for Rivers, Lakes and Estuaries
WASP is a free US EPA model for water quality in rivers, lakes, reservoirs and estuaries: nutrients, dissolved oxygen, eutrophication and toxics.
HY-8 — The Complete Guide: Free Hydraulic Design of Road Culverts
HY-8 is free US Federal Highway Administration software for culvert design: headwater, tailwater, outlet velocity, roadway overtopping and energy dissipators.
HEC-DSSVue — The Complete Guide: Free Time-Series Management for HEC Models
HEC-DSSVue is a free US Army Corps tool to view, edit, plot and process time series in HEC-DSS files, the data hub for HEC-RAS, HEC-HMS and HEC-ResSim.