CadQuery — The Complete Guide: Free Parametric CAD in Python Code, With STEP Export
CadQuery is a free Python library for building CAD models in code on the OpenCascade kernel: accurate parametric models with STEP export, for part families.
Guides and Articles
BRL-CAD — The Complete Guide: Military-Grade Solid Modelling, Open and Free
BRL-CAD is an open-source solid modelling system that began in the US Army: CSG modelling, ray tracing and geometric analysis of complex models. Free for all.
OrcaSlicer — The Complete Guide: Free 3D Print Preparation With Built-In Calibration
OrcaSlicer is a free open 3D printing slicer with profiles for many printers and built-in calibration tests for flow, temperature and retraction. Free.
Quarto — The Complete Guide: Free Living Engineering Reports Combining Code, Plots and Equations
Quarto builds reports, slides and websites from one file that mixes text, Python or R code, plots and equations. Change an input and the report updates.
Thonny — The Complete Guide: A Simple Free Python Environment for Beginners and Engineering Students
Thonny is a free Python IDE built for learning: Python comes included, it shows variables and each step, and it programs MicroPython boards like the Pico.
Xournal++ — The Complete Guide: Free Handwriting, Sketches and PDF Markup on a Tablet
Xournal++ is free open software for pen input on a tablet: lecture notes, worked solutions, sketches and review markups on PDF drawings, with LaTeX support.
ShareX — The Complete Guide: Free Screenshots, Annotation and Screen Recording for Engineers
ShareX is a free open screenshot tool for Windows: capture a region, window or scrolling page, add arrows and text, record GIFs, read text (OCR) and measure.
SumatraPDF — The Complete Guide: A Very Light, Fast Free PDF Reader for Drawings and Standards
SumatraPDF is a tiny free PDF reader for Windows that opens instantly, even heavy drawing sets. It also reads DjVu, ePub and XPS, with a portable version.
PDFsam Basic — The Complete Guide: Free Merging, Splitting and Rearranging of PDF Files
PDFsam Basic merges, splits, rotates and reorders PDF files on your computer, with no upload to a website. Ideal for submission sets. Free and open source.
Syncthing — The Complete Guide: Free File Sync Between Computers With No Cloud
Syncthing syncs folders directly between your own computers, encrypted, with no cloud server in between. Ideal for project folders. Free, open, no size limit.
Joplin — The Complete Guide: A Free, Encrypted Notebook for Sites, Projects and Study
Joplin is an open-source notes app and Evernote alternative: notebooks, tags, Markdown and end-to-end encryption on desktop and phone, synced as you choose.
Graphviz — The Complete Guide: Free Diagrams and Graphs Generated Automatically From Text
Graphviz draws diagrams from plain text: write nodes and links and it lays them out for you. Ideal for dependencies, state machines and fault trees. Free.