Editing AEC Free Software directory

== Introduction ==

This page lists software published under a [https://en.wikipedia.org/wiki/Free_software Free/libre] or [https://en.wikipedia.org/wiki/Open_source Open Source] (FLOSS) software license. It lists many types of packages for many purposes and is surely not comprehensive as the reach of FLOSS is extensive and always growing. If you know of anything we're missing please let us know by just adding it wherever you think it makes sense.

We are not the only group trying to promote free/libre software for AEC. Here are some other software lists: [https://help.ubuntu.com/community/UbuntuEngineering Ubuntu software list for engineering] (needs an update), [https://www.caelinux.com/CMS3/ CAELinux] is a distribution, forum and software list.

== General Purpose ==

If you're not familiar with Free & Open Source software useful for general use you can read our page on [[Open source software beginners]]

== Schematic design ==

Schematic design is defined as loose sketching, idea development, prototyping, and feasibility studies, without delving into the detailed geometrical or data attributes of a design.

{| class="mw-collapsible wikitable sortable"
! Logo
! Name
! Description
! Link to license
|-
| [[File:icon_blender_icon_64x64.png]]
| [[Blender]]
| Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, video editing and 2D animation pipeline.
| [https://www.blender.org/about/license/ GPLv3-only]
|-
| [[File:Firstdraft_logo.png|64px]]
| [http://dev.first-draft.xyz/ First Draft]
| A real time, web-based whiteboarding and markup tool.
| [https://gitlab.com/MeldCE/first-draft/-/blob/master/LICENSE GPLv3-only]
|-
| [[File:Excalidraw_logo.png|64px]]
| [[Excalidraw]]
| A real time, web-based whiteboarding and markup tool.
| [https://github.com/excalidraw/excalidraw/blob/master/LICENSE MIT]
|-
| [[File:icon_FreeCAD.png]]
| [[FreeCAD]]
| [[FreeCAD]] is an open-source parametric 3D modeler made primarily to design real-life objects of any size. Parametric modeling allows you to easily modify your design by going back into your model history and changing its parameters
| [https://github.com/FreeCAD/FreeCAD/blob/master/LICENSE LGPLv2-only]
|-
| 
| [https://github.com/brunopostle/homemaker-addon Homemaker add-on]
| The Homemaker is a [[:Category:Blender_Add-on|Blender Add-on]] that tries to automate the tedious work of designing buildings. Just indicate with simple geometry where you want walls, floors and roofs, and the software figures-out what building elements are needed to create that building. The result is an industry-standard IFC (BIM) model, suitable for taking the project towards construction.
| GPLv3
|-
| [[File:icon_krita_icon.png]]
| [[Krita]]
| Krita is a professional free and open source painting program. It is made by artists that want to see affordable art tools for everyone. It specialises in concept art, texture and matte painters, illustrations and comics.
| [https://invent.kde.org/graphics/krita/-/blob/master/COPYING GPLv3-only]
|-
| [[File:Icon_SweetHome3D_64x64.png]]
| [[Sweet Home 3d]]
| Sweet Home 3D is a free interior design application that helps you draw the plan of your house, arrange furniture on it and visit the results in 3D.
| [https://sourceforge.net/p/sweethome3d/code/HEAD/tree/trunk/SweetHome3D/LICENSE.TXT GPLv2-or-later]
|}

== GIS ==

Geographic Information Systems are used to interrogate GIS-level data, overlay multiple data sets, and integrate with BIM data.

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| 
| [[BlenderGIS add-on|BlenderGIS]]
| [[:Category:Blender_Add-on|Blender Add-on]]. Make the bridge between Blender and geographic data
| [[GPL-3.0]]
|-
|
| [https://github.com/SpaceGroupUCL/depthmapX depthmapX]
| depthmapX is an open-source and multi-platform spatial analysis software for spatial networks of different scales, from buildings and small urban areas to whole cities or states. At each scale, the aim of the software is to produce a map of spatial elements and connect them via relationship (for example, intervisibility, intersection or adjacency) and then perform a graph analysis of the resulting network. The objective of the analysis is to derive variables which may have social or experiential significance.
| [[GPL-3.0]]
|-
| [[File:Grassgis_logo_colorlogo_text_whitebg_64.png]]
| [[GRASS GIS]]
| Geographic Resources Analysis Support System (GRASS) from the U.S. Army Corps of Engineers' Construction Engineering Research Laboratory (USA/CERL)
| [[GPL-2.0]]
|-
| [[File:Icon_JOSM_64x64.png]]
| [https://josm.openstreetmap.de/ JOSM]
| JOSM is an extensible editor for OpenStreetMap (OSM) for Java 8+. It supports loading GPX tracks, background imagery, and OSM data from local sources as well as from online sources and allows to edit the OSM data (nodes, ways, and relations) and their metadata tags. 
| [[GPL-2.0]]
|-
| [[File:Icon mago3D 64x64.png]]
| [http://www.mago3d.com/eng/index.html mago3D]
| mago3D seamlessly integrates AEC (Architecture, Engineering, Construction) and 3D GIS in web browser using Cesium.
| [[Apache-2.0]]
|-
| 
| [https://www.openorienteering.org/ Open Orienteering]
| OpenOrienteering is a project developing a collection of tools which help with the creation of orienteering maps and the organization of orienteering events. 
| [[GPL-3.0]]
|-
| [[File:Icon_openstreetmap_64x64.png]]
| [https://openstreetmap.org OpenStreetMap]
| OpenStreetMaps is a community built map of the world, powering map data about roads, trails, cafés, railway stations, and much more, on thousands of web sites, mobile apps, and hardware devices.
| [[ODbL]]
|-
| [[File:Icon_qgis_64x64.jpeg]]
| [https://www.qgis.org/en/site/ QGIS]
| A Free and Open Source Geographic Information System to create, edit, visualise, analyse and publish geospatial information.
| [[GPL-2.0]]
|-
| [[File:Icon_qfield-logo.svg]]
| [https://qfield.org QField]
| An android app that syncs your QGIS projects to a mobile device and allows for in the field GIS data viewing and entry. 
| [[GPL-2.0]]
|-
| [[File:Icon saga.png]]
| [http://www.saga-gis.org/en/index.html SAGA]
| GIS System for Automated Geoscientific Analyses designed for the easy and effective implementation of spatial algorithms.
| [[GPL]]
|-
|
| [https://github.com/EL-BID/Building-Detection Raster Vision Building Detection]
| Code for running a Raster Vision experiment to train a model to detect buildings from satellite imagery in three cities in Latin America. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://github.com/EL-BID/Modelo-de-prediccion-de-crecimiento-urbano- Urban Growth Prediction Model]
| Code to run a model that predicts urban growth using a spatially-explicit stochastic land change modelling framework to produce projections of urban growth in a designated urban area and its surroundings. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://github.com/EL-BID/idb-osm-extraction-tool OpenStreetMap Extraction Tool]
| Friendly front-end for querying OSM features around Guyana from the Overpass API and extracting them as a Shapefile. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://github.com/hotosm/OpenMapKitServer OpenMapKit Server]
| OpenMapKit Server is the lightweight NodeJS server component of OpenMapKit that handles the collection and aggregation of OpenStreetMap and OpenDataKit data. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://github.com/EL-BID/Housing_Deficit Housing Deficit Estimation]
| Understanding housing deficit is crucial in creating housing policy. The code contained in this repo will apply a decisive methodology to determine levels of quantitative, qualitative, and total housing deficit based on census data, using census data as an example. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://github.com/EL-BID/GPE Georeferenced Program Evaluation]
| The GPE (Georeferenced Program Evaluation) R package includes functions that will allow the user to study various aspects of consumer or beneficiary behavior. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|-
|
| [https://jblindsay.github.io/ghrg/WhiteboxTools/index.html WhiteboxTools]
| WhiteboxTools can be used to perform common geographical information systems (GIS) analysis operations
| [[MIT]]
|-
|
| [https://github.com/EL-BID/urbanpy UrbanPy]
| UrbanPy is an open source project to automate data extraction, measurement, and visualization of urban accessibility metrics. Part of the Open Urban Planning Toolbox developed by the Inter-American Development Bank.
| CC-IGO 3.0 BY-NC-ND
|}

== Visualisation and Documentation ==

Open source tools useful for all graphical work involved in the process of architecture design. 3D render generation, image manipulation, page layout, etc. For a list of relevant pages including documentation and tutorials see [[:Category:Visualization and Documentation]]. For an overview of resources (software, textures, models, HDRI, etc.) read our article on [[FLOSS Visualisation and Documentation|Visualisation and Documentation]].

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| [[File:Appleseed logo.png|64px]]
| [https://appleseedhq.net/ Appleseed]
| Appleseed is an open source, physically-based global illumination rendering engine primarily designed for animation and visual effects. It provides individuals and small studios with a complete, reliable, fully open rendering package built with modern technologies.
| [[MIT]]
|-
| [[File:Icon blender icon 64x64.png]]
| [[Blender]]
| Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, video editing and 2D animation pipeline.
| [[GPL-2.0]]
|-
| 
| [https://www.blend4web.com/en/ Blend4Web(CE)]
| Blend4Web (Community Edition) is a free and open source framework for creating and displaying interactive 3D computer graphics in web browsers.
| [[GPL-3.0 ]]
|-
|
| [[Blender2Godot]]
| [[:Category:Blender_Add-on|Blender add-on]]. A free tool developed for quickly testing and deploying virtual / interactive visualizations, by linking Blender to the Godot Engine. Blender2Godot is a Blender3D addon that exports a Blender 3D scene to a Godot Engine project. This addon is in alpha state and thus still has a lot of bugs.
| [[GPL]]
|-
|
| [https://gist.github.com/yorikvanhavre/680156f59e2b42df8f5f5391cae2660b FCStd Import]
| FCStd Import is a Blender3D addon that imports FreeCAD files to a Blender project. This addon is in alpha state, developed by Yorik Van Havre and runs under Blender 2.80.
| [[unknown]]
|-
|
| [https://github.com/s-light/io_import_fcstd IO Import FCStd]
| IO Import FCStd is another Blender3D addon (script) that imports FreeCAD files to a Blender project. 
| [[MIT]]
|-
| [[File:Icon_gimp_64x64.png]]
| [https://www.gimp.org/ GIMP]
| GIMP is a cross-platform image editor available for GNU/Linux, OS X, Windows and more operating systems. GIMP provides the tools needed for high quality image manipulation. From retouching to restoring to creative composites, the only limit is your imagination. 
| [[GPL-3.0]]
|-
| [[file:Icon hugin-shadow 64x64.png]]
| [http://hugin.sourceforge.net/ Hugin]
| An easy to use cross-platform panoramic imaging toolchain based on Panorama Tools. With Hugin you can assemble a mosaic of photographs into a complete immersive panorama, stitch any series of overlapping pictures and much more. 
| [[GPL-2.0]]
|-
| [[File:Icon_inkscape_64x64.png]]
| [[Inkscape]]
| Inkscape is a professional vector graphics editor for Linux, Windows and macOS. Whether you are an illustrator, designer, web designer or just someone who needs to create some vector imagery, Inkscape is for you!
| [[GPL-2.0]]
|-
| [[File:Icon krita icon.png]]
| [[Krita]]
| Krita is a professional free and open source painting program. It is made by artists that want to see affordable art tools for everyone. It specialises in concept art, texture and matte painters, illustrations and comics.
| [[GPL-3.0]]
|-
| [[File:Icon Luxrender logo 64px.png]]
| [https://luxcorerender.org/ LuxRender]
| LuxCoreRender is a physically based and unbiased rendering engine. Based on state of the art algorithms, LuxCoreRender simulates the flow of light according to physical equations, thus producing realistic images of photographic quality.
| [[Apache-2.0]]
|-
|
| [http://www.mitsuba-renderer.org/ Mitsuba]
| Mitsuba 2 is a research-oriented retargetable rendering system, written in portable C++17 on top of the Enoki library. It is developed by the Realistic Graphics Lab at EPFL.
| [[GPL-3.0]]
|-
| [[File:Icon scribus 64.png]]
| [[Scribus]]
| Scribus is a page layout and desktop publishing program. Scribus supports professional publishing features, such as CMYK colors, spot colors, ICC color management and versatile PDF creation. Scribus has many unexpected touches, such as powerful vector drawing tools, support for a huge number of file types via import/export filters, emulation of color blindness or the rendering of markup languages like LaTeX or Lilypond inside Scribus. The Scribus file format is XML-based and open.
| [[LGPL-2.1]]
|-
|
| [https://f3d-app.github.io/f3d/ F3D]
| F3D is a fast and minimalist cross-platform open-source 3D viewer, It supports a range of file formats (including animated glTF, stl, step, ply, obj, fbx), and provides numerous rendering and texturing options. If you work with any kind of 3D data, you can use F3D to get a quick look at it as you would with a simple image viewer.
| [[BSD License]]
|-
|}

===Game engines===

Graphics game engines have been used in diverse areas of visualisation: simulators, educational software, interactive art, scientific visualisation and architecture.

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
|
| [https://armory3d.org/ Armory 3D]
| Armory is an open-source 3D engine focused on portability, minimal footprint and performance. The renderer is fully scriptable with deferred and forward paths supported out of the box.
| [[Zlib License]]
|-
|
| [https://godotengine.org/ GODOT]
| Godot is a 2D and 3D, cross-platform, free and open-source game engine released under the MIT license.
| [[MIT License]]
|-
|
| [https://www.ogre3d.org/ OGRE]
| Since 2001, OGRE has grown to become one of the most popular open-source graphics rendering engines, and has been used in a large number of production projects, in such diverse areas as games, simulators, educational software, interactive art, scientific visualisation, and others.
| [[MIT License]]
|-
|
| [https://www.panda3d.org/ Panda3D]
| Panda3D is an open-source, completely free-to-use engine for realtime 3D games, visualizations, simulations, experiments.
| [[BSD License]]
|-
|
| [https://upbge.org/ UPBGE]
| UPBGE is an open-source 3D game engine forked from old Blender Game Engine, deployed with Blender itself.
| [[GPL-2.0]]
|-
|}

===Virtual reality / augmented reality===

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
|
| [https://aframe.io/ A-Frame]
| A-Frame is a web framework for building 3D/AR/VR experiences.
| [[MIT License]]
|-
|
| [http://apertusvr.org/ ApertusVR]
| ApertusVR is an embeddable, open-source (MIT), framework-independent, platform-independent, network-topology-independent, distributed, augmented reality/virtual reality/mixed reality engine.
| [[MIT License]]
|-
|
| [http://www.artoolkitx.org/ ARToolKit]
| ARToolKit is an open-source computer tracking library for creation of strong augmented reality applications that overlay virtual imagery on the real world.
| [[LGPL-3.0]]
|-
|
| [http://opensimulator.org/wiki/Main_Page OpenSimulator]
| OpenSimulator is an open source multi-platform, multi-user 3D application server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols.
| [[BSD License]]
|-
|
| [https://www.openspace3d.com/ OpenSpace3D]
| OpenSpace3D is a free and open-source platform, designed to create virtual and augmented-reality applications or games. If you are a 3D artist, a designer, a lab researcher, or just someone with a lot of passion and curiosity, you do not need software development skills to use the platform.
| [[LGPL-3.0]]
|-
|}

== Geometry scanning and processing ==

Geometry scanning and processing relates to the task of laser scanning, as-built verification, point cloud manipulation, photogrammetry, and mesh reconstruction.

{| class="mw-collapsible wikitable sortable"
! 
! Name
! Description
! License
|-
| 
| [https://blender-addon-photogrammetry-importer.readthedocs.io/en/latest/index.html Blender-Photogrammetry-Importer]
| Blender addon to import reconstruction results of several libraries.
| [[MIT license]]
|-
| [[File:Icon_cloudcompare.jpg|CloudCompare|64x64px]]
| [[CloudCompare]]
| CloudCompare is a 3D point cloud (and triangular mesh) processing software. It was originally designed to perform comparison between two 3D points clouds (such as the ones obtained with a laser scanner) or between a point cloud and a triangular mesh. It relies on an octree structure that is highly optimized for this particular use-case. It was also meant to deal with huge point clouds.
| [[GPL-2.0]]
|-
|
| [https://demuc.de/colmap/ COLMAP]
| COLMAP is a general-purpose, end-to-end image-based 3D reconstruction pipeline (i.e., Structure-from-Motion (SfM) and Multi-View Stereo (MVS)) with a graphical and command-line interface. It offers a wide range of features for reconstruction of ordered and unordered image collections.
| [[BSD]]
|-
| [[File:GeoEasy_icon.jpg|GeoEasy|64px]]
| [http://www.digikom.hu/english/geo_easy_e.html GeoEasy] 
| Land survey import and processing software GeoEasy can import files from various Total stations, perform transformations and surveying calculations, create TINs from points and breaklines, do volume differences between TINs, etc.
| [[GPL-2.0]]
|-
| [[File:MeshlabjsLogo.png|Meshlab|64x64px]]
| [http://www.meshlab.net/ MeshLab]
| MeshLab is the open source system for processing and editing 3D triangular meshes. It provides a set of tools for editing, cleaning, healing, inspecting, rendering, texturing and converting meshes. It offers features for processing raw data produced by 3D digitization tools/devices and for preparing models for 3D printing.
| [[GPL-3.0]]
|-
| [[File:Odm-logo.svg|OpenDroneMap|64x64px]]
| [https://www.opendronemap.org/ Open Drone Map]
| Generate maps, point clouds, DEMs and 3D models from aerial images.
| [[AGPL-3.0]]
|-
| [[File:Point_cloud_visualizer.png|Point Cloud Visualizer|64x64px]]
| [[Point Cloud Visualizer]]
| [[:Category:Blender_Add-on|Blender add-on]]. Display, edit, filter, render, convert, generate and export colored point cloud PLY files in Blender. (Free version 0.9.3 [https://github.com/uhlik/bpy#point-cloud-visualizer-for-blender-280 for B3D 2.8])
| [[GPL-2.0]]
|-
| [[File:Regard3d_zopfli.png|64px]]
| [http://www.regard3d.org Regard3D]
| A free and open source structure-from-motion program. It converts photos of an object, taken from different angles, into a 3D model of this object.
| [https://sourceforge.net/projects/regard3d/ MIT]
|-
| 
| [[gradslam]]
| For usage in instant reality capture, gradslam is an open-source framework providing differentiable building blocks for simultaneous localization and mapping (SLAM) systems. We enable the usage of dense SLAM subsystems from the comfort of PyTorch.
| [[MIT license]]
|-
| [[File:Torch_logo.png|64x64px]]
| [https://github.com/nicolas-chaulet/torch-points3d Torch Points3D]
| "Torch Points3D, was developed to become the torchvision of point cloud data: a flexible and extensible framework for researchers and engineers alike working on point cloud-based machine vision." [https://github.com/nicolas-chaulet/torch-points3d Source Code]
| [https://github.com/nicolas-chaulet/torch-points3d/blob/master/LICENSE.md BSD]
|-
| [[File:Total_Open_Station.png|Total Open Station|64x64px]]
| [https://tops.iosa.it/ Total Open Station]
| Total Open Station (TOPS) downloads land survey data from total stations on your computer, from almost any operating system. Data you download can be archived as is, and exported to exchange formats (CSV, [[DXF]], GeoJSON, ...) for use in CAD or GIS software.
| [[GPL-3.0]]
|-
|}

== CAD / BIM Design Development ==

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| [[File:Icon_ArchiPack_64.png]]
| [[Archipack]]
| [[:Category:Blender_Add-on|Blender add-on]]. Quickly model parametric architectural objects in Blender, with a real-time, on-screen editing interface, designed for speed.
| [[GPL-3.0]]
|-
| [[File:BHoM_icon.png]]
| [[BHoM]]
| "The Buildings and Habitats object Model. A collaborative computational development project and collective experiment. By sharing and co-creating code we can better shape our environment and our future. We want technology to be open and accessible for all. And we think that by working together we can solve harder more impactful problems for the world."
| [[LGPL-3.0]]
|-
| [[File:BlenderBIM_Addon_logo.png|64x64px]]
| [[BlenderBIM Add-on]]
| [[:Category:Blender_Add-on|Blender add-on]]. An add-on for beautiful, detailed, and data-rich [[OpenBIM]] with [[Blender]]. Create data-rich [[Industry_Foundation_Class|IFC]]4 data to future-proof your BIM data and integrate with the rest of the [[OpenBIM]] ecosystem. 
| [[LGPL-2.0]]
|-
| [[File:Icon_CADTransform_64.png]]
| Blender Add-on: [[CAD Transform]]
| [[:Category:Blender_Add-on|Blender add-on]]. CAD like transform operations for blender 2.8+
| [[GPL-3.0]]
| 
|-
| [[File:Compas_icon_white.png|64px]]
| [https://compas.dev/ COMPAS]
| "A computational framework for collaboration and research in Architecture, Engineering, Fabrication, and Construction" 
| [[MIT]]
|-
| [[File:DynFreeCAD icon.svg]]
| [[DynFreeCAD]]
| [[Dynamo]] nodes for the FreeCAD API 
| [[MIT]]
|-
|
| [https://creativedesigner3d.com/ Home Builder Asset Library]
| A PyClone Blender asset library designed to help with architectural and interior design
| [[GPL-3.0]]
|-
| [[File:Icon BRL-CAD 64.png]]
| [https://brlcad.org/ BRL-CAD]
| BRL-CAD is a powerful open source cross-platform solid modeling system that includes interactive geometry editing, high-performance ray-tracing for rendering and geometric analysis, a system performance analysis benchmark suite, geometry libraries for application developers, and more than 30 years of active development.
| [[BSD]] / [[LGPL]]
|-
| [[File:Icon FreeCAD.png]]
| [[FreeCAD]]
| FreeCAD is an open-source, extensible, parametric 2D and 3D modeler primarily designed for mechanical engineering but which can be used in many different fields like machining, routing, 3D printing, finite element analysis, and of course, architecture and construction. Parametric modeling allows you to modify your design by going back into your model history and changing its parameters
|-
|
| [https://hypar-io.github.io/Elements/Elements/WhatIsElements.html Hypar Elements]
| Hypar Elements is a cross-platform library for creating building elements. It's meant to be used by architects, engineers, and other building professionals who want to write code that generates buildings.
| [[MIT]]
|-
| [[File:Icon_LibreCAD_icon.png]]
| [[LibreCAD]]
| LibreCAD is a free Open Source 2D CAD application for Windows, Apple and Linux. Support and documentation are free from our large, dedicated community of users, contributors and developers.
| [[GPL-2.0]]
|-
|
| [http://lx-viewer.sourceforge.net/ LX-Viewer]
| LX-Viewer (Linux Drawing Viewer) is a program that will allow you to open, view, print DXF files. The most important feature is that LX-Viewer allows you to manipulate your DXF data on the Linux platform. You may zoom and pan the drawing as you would in AutoCAD. Files can be saved to BMP, SVG and PNG formats. It runs on Linux and Windows platforms.
| [[GPL-2.0]]
|-
|
| Blender Add-on: [[MeasureIt-ARCH]]
| [[:Category:Blender_Add-on|Blender add-on]]. An expansion of Antonio Vazquez's MeasureIt add-on to add features to create Architectural Drawings and 3D measurements in Blender 2.8.
| [[GPL-3.0]]
|-
|
| [https://prism-app.io/ Prism]
| Prism is an open source app which accelerates the design process for precision manufactured housing (PMH) for London. It is free and easy to use and combines the Mayor of London’s spatial planning rules with precision manufacturer expertise to help you to quickly determine viable PMH options for your development.
| [[MIT]]
|-
| [[File:Icon QCAD.png]]
| [[QCAD]]
| QCAD is a free, open source application for computer aided drafting (CAD) in two dimensions (2D). With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schematics and diagrams. QCAD works on Windows, macOS and Linux.
| [[GPL-3.0]]
|-
| [[File:SolveSpace icon.svg|64x64px]]
| [[SolveSpace]]
| Small but capable parametric 2D/3D CAD (+ CAE & CAM) application for solid modeling. Highly interactive and well documented. Probably a good starting point for learning the basics of constraint-based modeling. Available for Linux, macOS and Windows.
| [https://github.com/solvespace/solvespace/issues/943#issuecomment-786406785 GPLv3-or-later]
|-
|
| [[Sorcar]]
| [[:Category:Blender_Add-on|Blender add-on]]. Sorcar is a procedural modeling node-based system which utilizes Blender and its Python API to create a visual programming environment for artists and developers. Heavily inspired by Side-FX Houdini, it presents a node editor with a variety of modular nodes to make the modelling workflow easier and fast.
| [[GPL-3.0]]
|-
| [[File:Icon speckle 64.png]]
| [[Speckle]]
| Speckle is an open source cloud-based data platform for AEC. It provides a method of liberating data from one platform to another in a quick, manageable, and efficient way. It works with Blender, ThreeJS, Rhino, Grasshopper, Excel, Unity, GSA, [[Revit]], and Dynamo.
| [[MIT]]
|-
| [[File:Sverchok.png|64x64px]]
| [[Sverchok]]
| [[:Category:Blender_Add-on|Blender add-on]]. Sverchok is a parametric tool for architects and designers for Blender. You can use it to program objects' shapes without knowing any programming languages. Sverchok has been inspired by Grasshopper from Rhino 3D and it uses a similar node-based visual programming principle. We are trying to bring this feature set to Blender users.
| [[GPL-3.0]]
|-
|
| [http://www.co-de-it.com/wordpress/code/blender-tissue Tissue]
| [[:Category:Blender_Add-on|Blender add-on]]. Create parametric and tessellated panels in Blender, for computational design.
| [[GPL-2.0]]
|-
| [[File:Icon_topologic_64x64.png]]
| [[Topologic]]
| Topologic is a software modelling library enabling hierarchical and topological representations of architectural spaces, buildings and artefacts through non-manifold topology.
| [[AGPL-3.0]]
|-
|
| [https://blenderartists.org/t/construction-lines-add-on-cad/1237928/ Construction Lines Add-on]
| [[:Category:Blender_Add-on|Blender add-on]]. Construction Lines Add-on for Blender, is currently under development (July 2020) and enables accurate modeling with a CAD-like workflow (though can be used in any modeling), building models from 2D primitives, setting out geometry with guide points and guidelines. A beta release is imminent. 
| unknown
|-
|
| [https://github.com/zamtmn/zcad ZCAD]
| ZCAD is a simple CAD program, written in Lazarus / FPC. It can open DXF files and save it as PDF, SVG... Also, it has some edition tools. 
| mLGPLv2
|}

== OpenBIM Management ==

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| -
| [[BCF-Plugin-FreeCAD]]
| A standalone plugin for the free, open source CAD tool [[FreeCAD]]. The aim is it to integrate collaboration in the BIM space through support of [[BIM Collaboration Format (BCF)|BCF]]."
| [[LGPL-3.0]]
|-
| [[File:Bimdata_logo.svg|BIMData|64x64px]]
| [https://bimdata.io/ BIMData]
| A simple online tool to deal with [[Industry_Foundation_Class|IFC]] and [[BIM Collaboration Format (BCF)|BCF]]. Has an electronic document management, issue management, visualise, check, and share digital models.
| [[LGPL-3.0]]
|-
| [[File:BIMserverorg.gif|BIMServer|64x64px]]
| [[BIMServer]]
| BIMserver.org is an open source development and has been a leader in the [[openBIM]] world for more than 10 years. The open source BIM community works together to create a best-of-class BIM-environment, including the Netherlands Organisation for Applied Scientific Research, TNO, who has been at the forefront of the development of this software for many years.
| [[AGPL-3.0]]
|-
| -
| [[BIMTester]]
| Write unit tests to check exchange requirements in [[Industry_Foundation_Class|IFC]]s and perform quality auditing of [[Industry_Foundation_Class|IFC]] data, based off Python behave.
| [[LGPL-2.0]]
|-
| -
| [https://github.com/opensourceBIM/BIMsurfer BIMSurfer]
| WebGL-based IFC model viewer with support for 3D tiles with a focus on high performance.
| [[MIT]]
|-
| [[File:Ifcopenshell logo.png|64x64px]]
| [https://blenderbim.org/download.html IFCCOBie]
| CLI tool to convert COBie data from an IFC file to spreadsheet format, and log all IFC errors that occur during the conversion process.
| [[LGPL-3.0]]
|-
| [[File:Ifcopenshell logo.png|64x64px]]
| [https://blenderbim.org/download.html IFCDiff]
| CLI tool to compare geometric and data differences between two IFC files and produce a diff report in JSON format.
| [[LGPL-3.0]]
|-
|-
| -
| [[IFC.js]]
| A front-end IFC viewer. Parsing is done via the browser.
| [[MIT]]
|-
| -
| [https://github.com/AECgeeks/ifc-pipeline IFC-Pipeline]
| A processing queue that uses [[IfcOpenShell]] to convert IFC input files into a graphic display using glTF 2.0 and BIMSurfer2 for web-based visualization.
| [[MIT]]
|-
| [[File:68747470733a2f2f62696d6d6172732e636f6d2f77702d636f6e74656e742f75706c6f6164732f323032312f30392f496663546f6f6c626f785f4170706c6f676f2e706e67.png|64x64px]]
| [https://youshengcode.github.io/IfcToolbox.Doc/#/ IFC Toolbox]
| IfcToolbox is a .Net kit of simple tools for processing IFC files. It provides tools to optimize, convert, split, relocate and anonymize IFC files easily. Based on open-source libraries like Xbim and IfcOpenShell.
| [[GPL-3.0]]
|-
| [[File:IFC%2B%2Btransparent120.png|IFC++|64x64px]]
| [[IfcPlusPlus|IfcQuery/IFC++]] ([[IfcPlusPlus|IfcPlusPlus]])
| C++ library and IFC viewer application for Windows and Linux
| [[MIT]] and closed source
|-
| [[File:Sloth.png|Sloth|64x64px]]
| [[Sloth]]
| Sloth is a [[BIM Collaboration Format (BCF)]] online viewer and report generator.
| [[MIT]]
|}

== Analysis and Simulation ==
See also [[Structural Analysis]] & [[Learn_about_environmental_analysis|Environmental Analysis]]

===Mesh generator and scientific data visualisation===
{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
|
| [https://gmsh.info/ Gmsh]
| Gmsh is an open source 3D finite element mesh generator with a built-in CAD engine and post-processor. Its design goal is to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization capabilities. Gmsh is built around four modules: geometry, mesh, solver and post-processing.
| [[LGPL-2.0]]
|-
|
| [https://www.paraview.org/ ParaView]
| ParaView is an open-source, multi-platform data analysis and visualization application. ParaView users can quickly build visualizations to analyze their data using qualitative and quantitative techniques. The data exploration can be done interactively in 3D or programmatically using ParaView’s batch processing capabilities.
| [[BSD]]
|}
===Structural, thermal and computational fluid dynamics (CFD) analysis===
{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
|
| [https://github.com/synthetik-technologies/blastfoam/ blastFoam]
| A CFD solver, built on top of OpenFOAM,for multi-component compressible flow with application to high-explosive detonation, explosive safety and air blast.
| [[GPL-3.0]]
|-
|
| [http://www.calculix.de/ CalculiX]
| CalculiX is a package designed to solve field problems. The method used is the finite element method. With CalculiX Finite Element Models can be built, calculated and post-processed.
| [[GPL-2.0]]
|-
| [[File:Icon_code_aster.png|64px]]
| [[Code_Aster]]
| Code_Aster offers a full range of multiphysical analysis and modelling methods that go well beyond the standard functions of a thermo mechanical calculation code: from seismic analysis to porous media via acoustics, fatigue, stochastic dynamics,etc.
| [[GPL-3.0]]
|-
|
| [https://www.code-saturne.org/cms/ Code_Saturne]
| Code_Saturne is the free, open-source software developed and released by EDF to solve computational fluid dynamics (CFD) applications. It solves the Navier-Stokes equations for 2D, 2D-axisymmetric and 3D flows, steady or unsteady, laminar or turbulent, incompressible or weakly dilatable, isothermal or not, with scalars transport if required.
| [[GPL-2.0]]
|-
|
| [https://www.csc.fi/web/elmer Elmer]
| Elmer is a multiphysical simulation software that includes physical models of fluid dynamics, structural mechanics, electromagnetics, heat transfer and acoustics, for example. These are described by partial differential equations which Elmer solves by the Finite Element Method (FEM).
| [[GPL-2.0]] (software) and [[LGPL-2.1]] (solver)
|-
|
| [https://energy.concord.org/energy2d/ Energy2D]
| "Energy2D is an interactive multiphysics simulation program that models all three modes of heat transfer—conduction, convection, and radiation, and their coupling with particle dynamics. Energy2D runs quickly on most computers and eliminates the switches among preprocessors, solvers, and postprocessors typically needed to perform computational fluid dynamics simulations." [https://github.com/charxie/multiphysics source]
| [[LGPL-3.0-only]] 
|-
|
| [https://www.epa.gov/water-research/epanet EPANet]
| EPANet is a software application used throughout the world to model water distribution systems. It was developed as a tool for understanding the movement and fate of drinking water constituents within distribution systems, and can be used for many different types of applications in distribution systems analysis.
| [[MIT]]
|-
|
| [https://sourceforge.net/projects/estru3d/ Estru3D]
| Program for structural analisys using the Stiffness Matrix Method. It has its own graphical interface and full GUI. Now beign translated to english. It is developed in Gambas3 basic only.
| [[GPL-3.0]]
|-
|
| [https://seamplex.com/fino/ Fino]
| Fino is a free and open source tool that uses the finite-element method to solve (i) steady-state thermo-mechanical problems, or (ii) steady or transient heat conduction problems, or (iii) modal analysis problems.
| [[GPL-3.0]]
|-
|
| [https://github.com/firemodels/fds Fire Dynamics Simulator (FDS)]
| Fire Dynamics Simulator (FDS) is a large-eddy simulation (LES) code for low-speed flows, with an emphasis on smoke and heat transport from fires.
| [https://github.com/firetools/blenderfds/blob/master/LICENSE GNU3.0]
|-
|
| [https://fenicsproject.org/ FEniCS]
| FEniCS is a computing platform for solving partial differential equations (PDEs). FEniCS enables users to quickly translate scientific models into efficient finite element code. FEniCS runs on a multitude of platforms ranging from laptops to high-performance clusters.
| [[LGPL-3.0]]
|-
|
| [http://frame3dd.sourceforge.net/ Frame3DD]
| Frame3DD is free open-source software for static and dynamic structural analysis of 2D and 3D frames and trusses with elastic and geometric stiffness. It computes the static deflections, reactions, internal element forces, natural frequencies, mode shapes and modal participation factors of two- and three- dimensional elastic structures using direct stiffness and mass assembly. Note there is also [https://nwtc.nrel.gov/pyFrame3DD pyFrame3DD] for Python.
| [[GPL-3.0]]
|-
|
|| [https://www.gempy.org/ GemPy]
|GemPy is a tool for generating 3D structural geological models in Python. As such, it enables you to create complex combinations of stratigraphical and structural features such as folds, faults, and unconformities. It was furthermore designed to enable probabilistic modeling to address parameter and model uncertainties.
| [[GPL-3.0]]
|-
| [[File:OpenFoam_logo.png|64px]]
| [[OpenFOAM]]
| OpenFOAM is the free, open source CFD software developed primarily by OpenCFD Ltd since 2004. It has a large user base across most areas of engineering and science, from both commercial and academic organisations. OpenFOAM has an extensive range of features to solve anything from complex fluid flows involving chemical reactions, turbulence and heat transfer, to acoustics, solid mechanics and electromagnetics.
| [[GPL-3.0]]
|-
|
| [https://opensees.berkeley.edu/ OpenSees]
| OpenSees is a software framework for developing applications to simulate the performance of structural and geotechnical systems subjected to earthquakes.
| UC Regents
|-
|
| [https://pythermalcomfort.readthedocs.io/en/latest/readme.html pythermalcomfort]
| pythermalcomfort is a Python package that allows users to calculate the most common thermal comfort indices in compliance with the main thermal comfort standards such as ASHRAE 55 and ISO 7730. For example, pythermalcomfort can be used to calculate: thermal comfort indices (e.g., Predicted Mean Vote, adaptive models, Standard Equivalent Temperature), local discomfort, clothing insulation, and psychrometric properties of air.
| [[MIT]]
|-
|
| [https://www.salome-platform.org/ Salome]
| SALOME is an open-source software that provides a generic Pre- and Post-Processing platform for numerical simulation. It is based on an open and flexible architecture made of reusable components.
| [[LGPL-2.1]]
|-
| [[File:Sparselizard64x64.png|64px]]
| [http://www.sparselizard.org/ sparselizard]
| Sparselizard is an efficient, highly multiphysics, hp-adaptive, open source C++ finite element library with demonstrated capabilities as of 2020/12 for at least fluid flow (creeping, laminar, transport), mechanics (isotropic, anisotropic, geometric nonlinearity, plasticity,...), electromagnetics (current flow, electro/magnetostatics, ac induction, antennas, electric motors, piezoelectricity, piezoresistivity,superconductivity,...), thermal, acoustics, FSI
| [[GPL-2+]]
|-
|
| [https://www.edf.fr/en/the-edf-group/world-s-largest-power-company/activities/research-and-development/scientific-communities/simulation-softwares?logiciel=10818 Syrthes]
| SYRTHES is a general thermal software dedicated to transient thermal simulations in complex solid geometries. EDF's R&D developed the software that can be used for a range of problems: nuclear (lifetime, nuclear waste disposal, new concepts, fuel transportation, etc.), electricity (transport, electromechanical devices, etc.), building efficiency, material physical properties, etc.
| [[GPL-2.0]]
|-
|
| [https://github.com/xcfem/xc XC]
| XC OSS is aimed directly at civil structural engineering. The software provides a set of structural analysis tools based on the finite element method and a framework to implement the design of structural members according to structural codes (Eurocodes, ACI, ...). Our objective is to develop an open tool that provides the engineer with unlimited freedom to take control of the structural analysis and to customize procedures.
| Project-specific FOSS
|
|-
| 
| [https://github.com/robbievanleeuwen/section-properties section-properties]
| section-properties is aimed at structural engineering. The software provides a tool to calculate sectional properties of arbitrary (complex) cross-sections using the finite element method. Some commonly used cross-section types are pre-built in the software (i.e. I-sections, etc) to simplify the calculation on those "simpler" cross-sections. The software also has the ability to perform a cross-sectional stress analysis given loading inputs.
| [[MIT]]

|-
| 
| [https://github.com/Krande/adapy ADA- PY]
| ADA - Assembly for Design & Analysis - A python library for working with structural analysis and design. Ada-py delivers an object-oriented framework for CAD/BIM/FEM modelling, interoperability and Finite Elements (FE) post-processing..
| [[GPL-3.0]]
|}

===Environmental analysis===
{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| [[File:Icon_ladybug_64x64.png]]
| [[Ladybug Tools]]
| Ladybug Tools is a collection of free computer applications that support environmental design and education connecting 3D Computer-Aided Design (CAD) interfaces to a host of validated simulation engines. Ladybug Tools can be used as a suite of Python libraries, or as a set of visual programming nodes with Blender (via Sverchok), or with proprietary software like Rhino (via Grasshopper) or Revit (via Dynamo).
| [[GPL-3.0]]
|-
| 
| [[OpenLCA]]
| The world’s leading, high performance, open source Life Cycle Assessment software. openLCA is an open source and free software for Sustainability and Life Cycle Assessment, with calculation of your Sustainability Assessment and/or Life Cycle Assessment, detailed insights into calculation and analysis results, best in class import and export capabilities; easy to share your models
Life Cycle Costing and social assessment smoothly integrated in the life cycle model, and more.
| [[MPL 2.0]]
|-
|
| [[Radiance]]
| Radiance is a suite of programs for the analysis and visualization of lighting in design. Input files specify the scene geometry, materials, luminaires, time, date and sky conditions (for daylight calculations). Calculated values include spectral radiance (ie. luminance + color), irradiance (illuminance + color) and glare indices. Simulation results may be displayed as color images, numerical values and contour plots.
| Project-specific FOSS
|-
| 
| [https://github.com/HoareLea SAM toolkit]
| SAM Toolkit is designed to help engineers to create Analytical Model.
| [[AGPL-3.0]]
|-
|
| [[VI-Suite]]
| [[:Category:Blender add-on|Blender Add-on]]. VI-Suite is a node-based add-on for performing environmental analysis in blender. The add-on acts as a pre/postprocessor for the EnergyPlus and Radiance simulation engines. Stable Version (0.4) released for blender 2.7, a version for blender 2.8 ([https://github.com/rgsouthall/vi-suite06 0.6]) is awaiting release.
| [[GPL-2.0]](citation needed)
|-
|}

===Energy analysis===
{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
|
| [[BIMxBEM]]
| A tool which analyze IFC data to feed local standards compliant energy related data to energy simulation softwares.
| [[LGPL-3.0-only]]
|-
|
| [https://cityenergyanalyst.com/ CEA]
| The City Energy Analyst (CEA) is an urban energy simulation platform and one of the first open-source computational tools for the design of low-carbon and highly efficient neighborhoods and districts. The CEA combines knowledge of urban planning and energy systems engineering in an integrated framework. This allows to study the effects, trade-offs and synergies of urban design options, building retrofits and energy infrastructure plans. https://github.com/architecture-building-systems/CityEnergyAnalyst
|  [[MIT]]
|-
| [[File:Eplus_logo_1.png]]
| [https://energyplus.net/ EnergyPlus]
| EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption—for heating, cooling, ventilation, lighting and plug and process loads—and water use in buildings.
| [[BSD]]-Style
|-
| [[File:OpenStudio logo-crop.png|64px]]
| [[OpenStudio SDK]]
| OpenStudio® is a cross-platform (Windows, Mac, and Linux) collection of software tools to support whole building energy modeling using [[EnergyPlus]] and advanced daylight analysis using [[Radiance]]. OpenStudio is an open source (LGPL) project to facilitate community development, extension, and private sector adoption. OpenStudio includes a Software Development Kit (SDK) that allows building researchers and software developers to quickly get started through its multiple entry levels, including access through C++, Ruby, and C#.
| LGPL-Style
|-
| [[File:OpenStudio%2BCoalition-logo-crop.png|64px]]
| [https://openstudiocoalition.org/ OpenStudioApplication & OpenStudio Sketchup Plugin]
| The OpenStudio Application is a fully featured graphical interface to OpenStudio models including envelope, loads, schedules, and HVAC. The OpenStudio SketchUp Plug-in is an extension to Trimble’s popular SketchUp 3D modeling tool that allows users to quickly create geometry needed for [[EnergyPlus]] using the built-in functionality of Trimble SketchUp including existing drawing tools, integration with Google Earth, Building Maker, and Photo Match. These two tools make use of the [[OpenStudio SDK]] and are being developed and maintained by the OpenStudio Coalition.
| LGPL-Style
|-
|}

===Traffic and pedestrian analysis/simulation===
{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| 
| [https://gama-platform.github.io/wiki/Home GAMA]
| GAMA is a modeling and simulation development environment for building spatially explicit agent-based simulations.
| [[GPL-3.0]]
|-
| 
| [https://www.jupedsim.org/ JuPedSim]
| JuPedSim is an open source framework for simulating, analyzing and visualizing pedestrian dynamics.
| LGPL-3.0 or later
|-
| 
| [http://www.massisframework.com/ MASSIS]
| MASSIS is a software framework that facilitates the simulation of scenarios with multiple agents (representing people, robots, sensors, etc.) in indoor environments (i.e., inside a building).
| GPL-3.0
|-
| 
| [https://eclipse.org/sumo SUMO]
| Simulation of Urban MObility (SUMO) is an open source, portable, microscopic and continuous multi-modal traffic simulation package designed to handle large networks.
| Eclipse Public License
|-
| 
| [https://github.com/UDST/urbansim UrbanSim]
| UrbanSim is an open source urban simulation system designed by Paul Waddell of the University of California, Berkeley and developed with numerous collaborators to support metropolitan land use, transportation, and environmental planning.
| New BSD License
|}

== Project Management ==

{| class="mw-collapsible wikitable sortable"
! Icons
! Name
! Description
! License
|-
| [[File:Icon_ganttproject_64.png|64px]]
| [https://www.ganttproject.biz/ GanttProject]
| GanttProject is a free desktop project scheduling application for small and medium businesses which need Gantt charts. 
| [[GPL-3.0]]
|-
| [[File:Icon_OpenProject_64x64.png]]
| [[OpenProject]]
| OpenProject is the leading open source project management software. Support your project management process along the entire project life cycle: From project initiation to closure. Includes support for [[BIM_Collaboration_Format|BCF]][https://www.openproject.org/openproject-bim-10-5/]
| [[GPL-3.0]]
|-
| [[File:Logo_ProjectLibre_64.png]]
| [https://www.projectlibre.com/ ProjectLibre]
| ProjectLibre is a free and open-source project management software system intended ultimately as a standalone replacement for Microsoft Project. ProjectLibre was developed by the founders of the abandoned project OpenProj.
| [[CPAL]]
|-
| 
| [https://www.projeqtor.org/en/ ProjeQtOr]
| ProjeQtOr is a collaborative and free open source project management software. It's a tool designed to be a Project Organizer as a Rich Internet Application. Web mode, once installed, you can work from the web browser.
| [[AGPL-3.0]]
|-
| 
| [https://github.com/gorovt/Qex_Studio Qex Studio]
| Software with a data base for cost analysis and estimate.
| [[GPL-3.0]]
|}

== Facility Management ==

{| class="mw-collapsible wikitable sortable"
! Icon
! Name
! Description
! License
|-
| 
| [https://sourceforge.net/projects/openjardin/ OpenJardin]
| OpenJardin is a free open source software for the management of a permaculture oriented garden (available languages: Français-Italiano-English). It allows interactive management of crop plots, with annual planning and crop rotation .
| [[GPL-3.0]]
|-
| [[File:Logo_openmaint.png|64px]]
| [[openMAINT]]
| openMAINT is the application for the management of mobile assets, plants and technical devices, furniture, etc., and the related logistical, economical and maintenance activities, scheduled and breakdown ones.
| [[AGPL-3.0]] & [[GPL-3.0]]
|-
|
| [https://github.com/vi-sense/vi-sense Vi-Sense]
| Vi-Sense is a project that visualizes data of heating systems in a 3D model of the building they're installed in. Technicians or system administrators get an overview of all sensors located in a building, can take a closer look at the measured values of these sensors, and get information about data anomalies that indicate potential errors. The combination of the 3D representation of buildings and the visualization of measured values in a timeline makes it possible to perform detailed analyses of error sources such as the failure of heating or pump systems. In addition, sensor states in the building model are supported by color highlighting, which ensures a quick orientation and an intuitive overview.
| [[MIT]]
|}

== Software Development ==

If you are a software developer, you may be interested in a wide variety of free software libraries available to aid development of new free software tools in the AEC industry. Tools include file format parsers, geometry kernels, a visualisation libraries. See [[free software libraries for AEC software development]].

== Extensions to proprietary software ==

Some software is distributed as free software, but only as an extension, an add-on, plug-in, or only operating in conjunction with proprietary software. As it cannot be used practically without proprietary software, it is not considered "fully" free software. Sometimes, though not always, they are released as open source as a marketing strategy to seem more open, or as a way to attempt to get free community contributions to an otherwise proprietary core. See the directory of [[free software extensions to proprietary software]].

[[Category:Directories]]
[[Category:Visualization_and_Documentation]]
[[Category:BIM Collaboration Format (BCF)]]