In the software development world, there exists a notion that applications can always be improved, especially if this role is shared among multiple parties. This principle underlies the ‘open source’ concept, which has seen the rollout of numerous applications. Open source software license confers unfettered access to the source code as well as the compiled form of the program. It further gives the licensee the right to modify, distribute, and redistribute the source code, subject to certain conditions outlined in the official definition. By supporting access to the source code and, by extension, modification, an open-source software license promotes community-driven support, faster iteration, and flexible software development. These benefits permeate every sphere wherein software is integral, including the computer-aided design world.
Design professionals, such as architects, engineers, product designers, and drafters, with a technical background may want to work with software they can modify as they see fit. They may prefer software to which they can add features and contribute to the development process. If this describes your niche interest, you have come to the right place – this article will discuss the best open-source CAD software in the market today. We will also detail their use cases and the criteria we used to come up with the list. That said, it is crucial to demystify a common misconception that open-source software is free or vice versa: That is not always the case. Thus, if you are looking for free CAD software, consider going through our detailed article on the 14 top free CAD packages to download. However, if you are specifically looking for the best open-source CAD software, let’s get into it.
Table of Contents
Criteria for Selecting the Best Open-Source CAD Software
Our selection of the best open-source CAD software applications is anchored on a combination of four factors that include:
1. Functionality and Features
Good CAD software should offer powerful tools that enable users to create 2D drawings or 3D models. And when it comes to 3D modeling, the application should support simulations, renderings, analysis, and more. In this regard, our list of the best open-source CAD software includes software that offers a wide selection of toolsets that makes possible the seamless creation and editing of 2D drawings and 3D models. 3D modeling software also supports the above-mentioned capabilities.
2. User-Friendliness and Ease of Use
Some open-source CAD software, such as BRL-CAD and OpenSCAD, are operated using commands issued via a built-in terminal. For instance, to create an object such as a cylinder, one must specify the coordinates of the base, its radius, and more. While this may be appealing to some users with a technical background or those who can create a mental image of the object, it is not user-friendly to all users and may not be easy to learn or use.
Against this background, our selection of the best open-source CAD software comprises applications with a graphical user interface (GUI), complete with a workspace (model space). This workspace allows users to draw objects by dragging the mouse and stipulating the dimensions. Thus, user-friendly software visually represents users’ ideas, eliminating the need to create mental images. In this way, they are easy to use and learn.
3. Community Support and Development
Community support is integral to ensuring open-source software applications are up to date. For example, community members make changes to the codebase, whether small or large, that fix bugs, introduce new features, and improve the stability of the software. At the same time, the contributors help identify issues, prepare technical and end-user documentation, and translate the software. Given the scope of their responsibilities, a vibrant community is extremely important. For this reason, our list of the best open-source CAD software includes applications with a vibrant community, complete with developer and user forums.
4. Licensing and Legal Considerations
For a program to be considered open source, it must give users the freedom to share, copy, and modify the software. Thus, our list only includes applications whose licenses confer these rights to users. In most cases, they use GNU General Public Licenses.
Top 5 Open-Source CAD Software Options
What is FreeCAD?
FreeCAD is the first solution in our list of the five best open-source CAD software. It is a multi-platform open-source 3D parametric modeling software application. It is available under the GNU Lesser General Public License (LGPL). This free software license grants licensees the rights to copy, download, read, analyze, modify, or redistribute software’s source code. This means you can alter the content of the source code in such a way that the software performs unique tasks that may not be available to other users. For this reason, FreeCAD is considered highly customizable and extensible.
Do note, however, that if you want to make modifications you wish to see added to the official code, the changes you make must be approved by the FreeCAD developers. To do this, engage in discussions about your ideas and intentions with the FreeCAD developers via the FreeCAD forum.
The FreeCAD source code is available for download on FreeCAD’s GitHub repo, where code management, pull requests, and new code deployment are undertaken. The software is programmed using C++ but contains some Python-driven elements. It also relies on a number of open-source libraries that must be installed prior to compilation. These include Open Cascade, used to create and manage solid geometry; Coin3D, used to manage the 3D view; and Qt, which creates the software’s graphical user interface (GUI).
Who Uses FreeCAD?
FreeCAD is designed to be deployed in a number of use cases, ranging from mechanical engineering to architecture and product design. It is, therefore, used by mechanical drafters, architects, product designers, and mechanical engineers. Moreover, FreeCAD is appropriate for programmers who may wish to contribute by writing code or reporting and triaging bugs, or technical writers, who can contribute to the open source project by working on the software’s documentation or translating the existing documentation. Nonetheless, from a CAD perspective, the capabilities are particularly appealing.
How to Download FreeCAD?
To download FreeCAD, visit the official website’s download webpage. The page contains three links for each supported platform – Windows, macOS, and Linux. Click on the appropriate link to start downloading the executable file.
Capabilities of FreeCAD
The capabilities of FreeCAD include the following:
- The software lets design professionals design real-life objects of any size
- Users can sketch geometry-constrained 2D shapes and use them as the foundation to build other objects
- It can read and write to multiple neutral file formats, namely STEP, STL, SVG, DXF, OBJ, IGES, DAE, IFC, and more
- FreeCAD offers modern finite element analysis (FEA) tools
- The software has experimental computational fluid dynamics (CFD) tools
- It has dedicated BIM capabilities
- FreeCAD supports CNC or CAM workbenches
- It is capable of performing robot simulations
Strengths of FreeCAD
- It has a vibrant online forum
- FreeCAD’s developers’ documentation and users’ documentation are readily available
- The software’s GitHub repository contains plenty of information and resources
- The open-source community regularly updates and modifies some aspects of the source code
- The software is free to download and use
- It offers numerous features and capabilities, including FEA and CFD tools, support for CNC/CAM workbenches, robot simulations, and more
- It is a multi-platform CAD software available for Windows, macOS, and Linux
Weaknesses of FreeCAD
- It can be slow, especially when working with large projects
- FreeCAD lacks some features that can be found in other modeling software
- It does not have scheduled yearly updates (even though contributors regularly modify the source code)
What is LibreCAD?
LibreCAD is a free, multi-platform open-source CAD application available under the GNU General Public License version 2 (GLPv2). The software is primarily meant for 2D design and drafting – it enables users to draw lines, circles, arcs, polylines, and splines, as well as use modification tools such as fillet, trim, offset, mirror, move, copy, and scale. Other capabilities include dimensioning, layer management, hatching, and block creation.
The LibreCAD open-source project began around 2010 as a fork (copy) of one of the versions of QCAD. At that time, this project, originally known as CADuntu, aimed to build CAM capabilities into the QCAD version to facilitate its use with a Mechmate CNC router. But the CADuntu name only stuck for several months before being renamed LibreCAD.
The software’s GLPv2 license grants license holders the right to modify and/or redistribute the source code/compiled program. It is this freedom to modify that creates an open-source community that, in turn, works on bugs and features, prepares documentation, and localizes the software by translating it into various languages. To put it more concisely, LibreCAD is a non-profit, community-driven project that relies on input from contributors and sponsors.
Who Uses LibreCAD?
While C++ programmers who contribute to the project get to also interact with the software, they are not the intended users. LibreCAD is primarily CAD software designed to facilitate 2D drawing and design. For this reason, it is used by CAD drafters and engineers.
How to Download LibreCAD
There are two main approaches you can use to download LibreCAD:
- SourceForge: Once you click the ‘Download’ button, SourceForge, a software platform that allows users to download open-source software, automatically recognizes your operating system and prepares the appropriate file for download.
- LibreCAD’s GitHub repo: This is a manual approach to downloading the file. The repository contains three links to executable files corresponding to each supported operating system – Linux, macOS, and Windows. Clicking on the appropriate link initiates the download process.
Capabilities of LibreCAD
- It can read DWG and DXF files and write DXF, PDF, and SVG files
- LibreCAD supports hatching, dimensioning, text annotation, block creation and insertion, and layer management
- It has a library to manage standard components, such as screws and windows, through blocks
- LibreCAD offers snap functions
- It has customizable toolbars
- It supports tens of languages – a total of 30
Strengths of LibreCAD
- LibreCAD’s user interface is translated into over 30 languages
- It has a highly customizable GUI
- It is free and open source
- LibreCAD can read proprietary DWG files
Weaknesses of LibreCAD
- It is primarily a 2D CAD software
- The updates to the official source code are irregular and far between – the development process is slow
- Users report slow performance and frequent crashes
- Although LibreCAD is one of the best open-source options, it lacks some features found in other software
- LibreCAD lacks rendering capabilities
3. QCAD Community Edition
What is QCAD Community Edition
Like its fork, LibreCAD, QCAD is primarily devoted to 2D design and drafting. However, unlike LibreCAD, which is wholly open source, QCAD is not. There are three editions of QCAD, namely QCAD Professional, QCAD/CAM, and QCAD Community Edition. The former two editions, being commercial and proprietary software, are available only after purchase on the QCAD online store.
The QCAD Community Edition, on the other hand, is a free, open-source software program whose source code is publicly available on QCAD’s GitHub repo. It is available under GPL version 3, which permits the use, modification, distribution, and redistribution of the software.
QCAD traces its origin to October 1999, when version 1 of the software was released. In September 2003, version 2 was released, followed by version 3 in July 2012. The latest release of QCAD (3.28) is an iteration of the third version. The software was designed to be modular, extensible, and portable, tenets that it has carried since. It has an intuitive interface and is easy to use yet powerful. These attributes inform its status as one of the best open-source CAD solutions in the market today.
Who Uses QCAD Community Edition
As a 2D CAD system, QCAD Community Edition is meant for 2D design and drafting. Thus, it is used by engineers, designers, and architects to create technical drawings for mechanical parts, interiors, buildings, schematics, and diagrams. Moreover, being an open-source project, this software is used by programmers who wish to contribute. The source code is programmed using C++.
How to Download QCAD Community Edition
QCAD Community Edition is a multi-platform software that works on Linux, Windows, and macOS. To download the application, head over to the QCAD downloads webpage, download the trial version for your operating system, and remove the QCAD Professional add-on running in trial mode. (To remove the add-on, click the Remove button in the Trial widget and follow the instructions.)
Alternatively, you can compile your own QCAD package by downloading the zip files containing the QCAD and Qt source codes. This approach is primarily intended for developers.
Capabilities of QCAD Community Edition
Now that you have downloaded and installed the software, what features will you likely encounter? QCAD Community Edition is one of the best open-source CAD software options focusing on 2D design. This is because it offers several features and tools, including:
- Measuring tools
- Object snaps
- Part library with more than 4800 CAD parts
- Support for layers and blocks
- Tools for creating and modifying lines, arcs, circles, polylines, splines, ellipses, texts, hatches, fills, raster images, dimensions, and more
- Ability to read and write DXF, DWF, DWG, and PDF files
- Printing capabilities, e.g., printing to scale and printing on multiple pages
Strengths of QCAD Community Edition
- QCAD Community Edition is free and open source
- It produces detailed technical drawings thanks to its myriad features and tools
- It is easy to use, yet powerful.
Weaknesses of QCAD Community Edition
- It is primarily a 2D CAD software
- Although QCAD Community Edition is one of the best open-source CAD solutions, the paid QCAD tiers offer superior features and capabilities
- Users report that it can be buggy and slow
What is Blender?
Blender is a free, open-source computer graphics (CG) software application that enables artists and designers to create 3D CG content. As such, it is less focused on manufacturing and construction, and more geared towards interactive and creative CAD. As a hub for creating 3D models and graphics, it supports the entire ensemble, including modeling, sculpting, rigging, animation, simulation, motion tracking, rendering, and compositing. So advanced are the supported tools that Blender can be used for game creation and even video editing. Moreover, thanks to its Python API, Blender supports scripting, which enables users to customize the application and write specialized tools.
Blender is a 100% community-driven project guided by the GNU GPL license. The license empowers contributors to make small and large modifications to the code base, which result in better usability, bug fixes, and new features. (The source code is hosted on Blender’s projects website and mirrored on a GitHub repo.) In addition, the Blender community helps with writing and organizing the technical and end-user documentation. Volunteers also contribute by translating existing documentation into various languages.
Who Uses Blender
Blender is suitable for VFX experts, animators, students, professional 3D modelers, artists, and hobbyists. It is also ideal for creative programmers who want to write specialized tools based on the existing source code.
How to Download Blender
Blender is a multi-platform software available on Linux, Windows, and macOS. To download Blender, visit the Download webpage and click the download icon. (The website automatically recognizes your operating system and displays a button that links to the version of the installer that corresponds to your OS.)
Capabilities of Blender
- An extensive modeling toolset that enables the creation, transformation, and editing of models
- Digital sculpting tools such as support for 20 different brush types, dynamic topology (a dynamic tessellation sculpting method that adds and removes details on the go), masking, and a dedicated workspace
- Blender’s ray-trace-based production render engine called Cycles offers ultra-realistic rendering
- Animation toolset, including sound synchronization, character animation pose editor, forward/inverse kinematics for fast poses, rigging, motion paths, and more
- The ability to draw 2D in 3D, combining the power of 2D and 3D; Blender refers to this capability as Story Art
- Visual effects (VFX), including compositing and motion tracking
- Simulations for rain, fire, smoke, fluid, cloth, crumbling building, or full-on destruction
- Video editing: the software comes with a built-in video sequence editor
Strengths of Blender
- It is free and open source
- Blender has powerful modeling, rendering, simulation, sculpting, and animation tools
- Up-to-date technical and end-user documentation
- A large collection of free tutorials
- Strong community support for both contributors (developers) and users
Weaknesses of Blender
- The wide array of tools can be overwhelming, and this often results in a steep learning curve
- The user interface can sometimes feel complicated, especially given it houses numerous tools
- It is sometimes unable to handle large projects, as it becomes slow
- Blender can occasionally be buggy and may crash
What is SALOME?
With more than 150,000 downloads from multiple countries in 2021 alone, SALOME is a somewhat popular open-source software application. Primarily used for numerical simulation, it also includes modules that enable users to create parametric models, mesh shapes, and visualize results. Its modules can be directly accessed via an easy-to-use GUI or Python scripts. The existence of these modules makes customization easy, as users can create domain-specific applications by assembling two or more modules based on their needs.
SALOME is available under the GNU LGPL, which allows for the copying, modification, distribution, and redistribution of the software. For this reason, the application is developed collaboratively as part of an open-source project that started in the early 2000s. The project began as a way of implementing solutions to multi-physics problems and facilitating the integration of specific calculation solutions to these problems. Currently in its ninth version, SALOME has indeed evolved, with the community playing a significant role in making this possible.
Who Uses SALOME?
As one of the best open-source CAD software, Salome is designed for engineers and researchers seeking a free, open-source solution for CAD modeling, visualization, coupling of multi-physics phenomena, uncertainty studies, and more. It is primarily designed for numerical simulation in industries that require high-performance methods in electromagnetism, structural mechanics, fluid mechanics, and more.
How to Download SALOME
To download SALOME, you must fill in a download form that enables the developer to better know the users interested in the software. You can also choose to remain anonymous, in which case you won’t be prompted to complete the form. Upon clicking Submit, the website will direct you to a new webpage that contains a button allowing you to download the software. The form can be found on the SALOME platform’s download webpage.
Capabilities of SALOME
- SHAPER, a parametric and variational CAD modeler
- SMESH, a mesh generator or editor suited for finite element and finite volume methods
- PARAVIS module, which enables scientific visualization and analysis of results as part of computational simulation
- Specialized data assimilation calculations for parameter calibration or field interpolation
- SOLVERLAB, a module for solving partial differential equations
- Numerical simulation
- Uncertainties studies using the OpenTURNS and Uranie libraries
Strengths of SALOME
- Helpful resources are available, such as developers’ documentation, video tutorials, and users’ documentation
- It is highly customizable
- SALOME is free and open-source
- It has impressive CAD modeling and mesh generation capabilities
Weaknesses of SALOME
- SALOME is only available on Linux and Windows
- The Git repositories are accessible in read-only mode using HTTP or HTTPS protocols and are not hosted or mirrored on GitHub
- Users report that it is buggy, especially on Windows
Open-source licenses are prevalent in the software development realm, allowing users to copy, download, modify, distribute, and redistribute both the software and its source code. This approach leads to beneficial outcomes, such as the introduction of new features and bug resolution. Such community-driven projects can also be found in the CAD world, where numerous free, open-source CAD software options exist. This article examines the top five open-source CAD software, including FreeCAD, LibreCAD, QCAD, Blender, and SALOME. Additionally, it delves into each program’s capabilities, strengths, and weaknesses and provides guidance on downloading each application.