A few days ago, while processing some legacy DWG files left by the previous data team in QGIS, I was reminded of the company's AutoCAD replacement project from three years ago. That project, based on a open-source CAD software, was ultimately shelved due to the high costs of complex development. It got me thinking: it's already 2026, how have open-source CAD software options evolved? Are there any outstanding open-source alternatives? With these questions in mind, I searched some information. If you have other better recommendations, feel free to leave a comment for discussion.
FreeCAD
FreeCAD is currently one of the most popular open-source 3D CAD software, released under the LGPL license. It is suitable for fields like engineering, architectural design, mechanical design, and product design. Its core feature is parametric modeling, where all design elements are defined by parameters and formulas. When a parameter is changed, all dependent design elements update automatically. It comes with many features and tools for professional applications, including part design, assembly, motion simulation, material property management for mechanical engineering, and supports BIM (Building Information Modeling) workflows.
It currently supports Windows, macOS, and Linux platforms. Notably, its excellent support for BIM and IFC standards makes it a top choice for city base modeling. Those working on BIM+GIS applications should definitely check it out.
Official website: https://www.freecad.org/
LibreCAD
If you only need to handle common .dwg or .dxf map base layers and want to avoid bloated installation packages, LibreCAD remains a solid choice in 2026. It is a free and open-source 2D drafting CAD software, seen as a lightweight alternative to classic AutoCAD, primarily used for creating planar engineering drawings, layout plans, and vector designs.
It is also natively cross-platform (including domestic Linux systems like UOS and Kylin). The current stable version is 2.x, with the next-generation 3.x version under development. It handles complex 2D line drawings very smoothly and is often used as a post-processing tool for exported map features.
Official website: https://librecad.org/
QCAD
Does it remind you of QGIS? Indeed, it's also developed with Qt. Like LibreCAD, QCAD is an open-source, free 2D technical drawing CAD software, released under the GPLv3 license. It provides professional 2D CAD capabilities suitable for various technical drawing scenarios. QCAD features a clean, user-friendly interface with comprehensive functionality, making it particularly suitable for engineers and designers requiring precise 2D drafting.
The QCAD community remains relatively active. The software is compact and supports Windows, Linux, and macOS.
Official website: https://www.qcad.org/en/
Blender
Including Blender here might seem slightly off-topic, as it is primarily known as 3D creation software. However, it also possesses powerful CAD capabilities. Through plugins like CAD Sketcher, BlenderBIM, Archipack/Archimesh, it can achieve some CAD functionalities. For example: you can sketch as you would in SolidWorks, define constraints (vertical, parallel, tangent) and precise dimensions; its support for the industry-standard IFC format allows it to handle real architectural engineering data, among other features.
It is also available for Windows, macOS, and Linux. I highly recommend taking some time to learn this software; I'm quite optimistic about its potential.
Official website: https://www.blender.org/
OpenSCAD
OpenSCAD is a software particularly suited for users who prefer designing 3D models through precise control. Unlike traditional GUI-based 3D modeling tools, OpenSCAD does not rely on visual editing or drag-and-drop. Instead, it uses a descriptive scripting language to define the geometry of objects. This approach makes OpenSCAD very powerful for creating 3D models with specific parametric and repeatable precision requirements.
Some common applications include batch generating standardized components based on GIS vector data (e.g., generating streetlight models along road centerlines), although the learning curve is not trivial.
Official website: https://openscad.org/
BRL-CAD
BRL-CAD is a premier open-source Constructive Solid Geometry (CSG) modeling system with over 40 years of history, originally developed by the U.S. Army. It is renowned for its exceptional physical accuracy and powerful geometric analysis capabilities, making it especially suitable for applications requiring high-precision geometric calculations. Recently, it has launched a brand-new graphical user interface (Arbalest), moving away from its historically command-line-focused era. Those interested might want to give it a try.
From what I know, some of its uses focus on engineering analysis (such as volume and mass calculations). It is also cross-platform.
Official website: https://brlcad.org/
Summary
Currently, in other specialized niches, there are many open-source software options for CAD replacement. They often excel in specific areas and can replace parts of AutoCAD's functionality. There are many more that I cannot list exhaustively here; please feel free to comment if you know of any particularly useful ones. However, overall, AutoCAD and its ecosystem remain quite robust. After all, fundamental industrial software like this isn't something that can be overtaken overnight. Also, I haven't listed domestic (Chinese) CAD software here; if there are good ones, please recommend them!