PyPSA
PyPSA community (TU Berlin)
Optimisation of power and energy systems — economic dispatch, capacity expansion, storage and sector coupling.
Get it from the vendorThis is the heart of the guide: software anyone can download and use at full capability, including for paid commercial work, with no time limit, no registration and no licence key.
Most records here are open source — the code is visible, you can check what it does, and if the project closes tomorrow the code remains. Others are government or vendor software distributed free but not open; entirely free to use, simply not modifiable.
What is still worth checking: whether the tool works to the code you submit under, and whether it produces a report you can attach to a file. "Completely free" describes the licence, not the fit to your needs.
644 results
pyslope
Jesse Bonanno
Python library for 2D slope stability by Bishop’s method, with layers, water table, loads and critical surface search.
Get it from the vendor
pyStrata
Albert Kottke
One-dimensional seismic site response of a soil column — equivalent-linear, time series and RVT, in Python.
Get it from the vendor
Python
Python Software Foundation
The language behind most modern engineering computation, and its full ecosystem.
Get it from the vendor
Pyzo
Pyzo Project
A lightweight Python environment for scientific and engineering work.
Get it from the vendor
Qalculate!
Hanna Knutsson
A smart desktop calculator — full unit conversion, physical constants, uncertainty propagation and symbolic algebra.
Get it from the vendor
QDirStat
Stefan Hundhammer
A WinDirStat-style disk-usage map for Linux: a folder tree and a coloured treemap that show what takes up space.
Get it from the vendor
QElectroTech
QElectroTech Project
Draws electrical panel and control diagrams from standard symbol libraries.
Get it from the vendor
QField
OPENGIS.ch
QGIS in the field — data collection on a phone or tablet, offline.
Get it from the vendor
QGIS
QGIS.org
Open-source GIS for spatial analysis, layer work and map production.
Get it from the vendor
QGroundControl
Dronecode Project
Ground control station for PX4 and ArduPilot drones — mission planning, area surveys and corridor scans for photogrammetry and mapping.
Get it from the vendor
QModMaster
QModMaster (open-source project)
Modbus RTU and TCP master with a bus monitor — for testing PLCs, energy meters, drives and sensors.
Get it from the vendor
QOwnNotes
QOwnNotes project
Markdown notes as plain text files, with Nextcloud sync, to-do lists and encryption.
Get it from the vendor
qpdf
qpdf project (Jay Berkenbilt)
Command-line tool to repair, encrypt and decrypt, merge and split PDFs and inspect file structure — without changing the content.
Get it from the vendor
QSPICE
Qorvo
A fast mixed-signal SPICE simulator with digital blocks in C++ and Verilog — free, including for commercial use.
Get it from the vendor
Quarto
Posit
Technical reports from code and data — Python, R or Julia into Word, PDF, HTML and slides.
Get it from the vendor
Qucs-S
Qucs-S Project
Circuit simulation with a graphical schematic front end over SPICE engines.
Get it from the vendor
QucsStudio
Michael Margraf
A circuit and RF simulator: DC, AC, transient, S-parameters and harmonic balance, with microstrip tools and filter synthesis. Free even for commercial use.
Get it from the vendor
R
R Foundation
The leading language for statistics and data analysis — quality control, experiment analysis, reliability and forecasting.
Get it from the vendor
Radiance
Lawrence Berkeley National Laboratory
Physically accurate daylight and lighting simulation — the basis for green building light calculations.
Get it from the vendor
Raven Hydrological Framework
University of Waterloo (James Craig and team)
Flexible framework for catchment hydrological models: from a simple lumped model to a semi-distributed model with snowmelt, routing and reservoirs.
Get it from the vendor
RawTherapee
RawTherapee project
A free RAW developer with a 32-bit processing engine, fine colour and detail control and batch processing of photos.
Get it from the vendor
Ray Optics Simulation
Ray Optics Simulation Project
Light ray simulation in the browser — lenses, mirrors and optical fibres.
Get it from the vendor
rclone
rclone project
Sync and copy files to 70+ cloud storage services from the command line, and mount cloud drives as local disks.
Get it from the vendor