nanoCAD!

FreeCAD is a general purpose parametric 3D CAD modeler. The development is completely Open Source (LGPL License). FreeCAD is aimed directly at mechanical engineering and product design but also fits in a wider range of uses around engineering, such as architecture or other engineering specialties.FreeCAD features tools similar to Catia, SolidWorks or Solid Edge, and therefore also falls into the category of MCAD, PLM, CAx and CAE. It is a feature based parametric modeler with a modular software architecture which makes it easy to provide additional functionality without modifying the core system.As with many modern 3D CAD modelers it has many 2D components in order to sketch 2D shapes or extract design details from the 3D model to create 2D production drawings, but direct 2D drawing (like AutoCAD LT) is not the focus, neither are animation or organic shapes (like Maya, 3ds Max, Blender or Cinema 4D), although, thanks to its wide adaptability, FreeCAD might become useful in a much broader area than its current focus.FreeCAD makes heavy use of all the great open-source libraries that exist out there in the field of Scientific Computing. Among them are OpenCascade, a powerful CAD kernel, Coin3D, an incarnation of Open Inventor, Qt, the world-famous UI framework, and Python, one of the best scripting languages available. FreeCAD itself can also be used as a library by other programs.FreeCAD is also fully multi-platform, and currently runs flawlessly on Windows and Linux/Unix and Mac OSX systems, with the exact same look and functionality on all platforms. »

LibreCAD (originally QCad then CADuntu) is an open source 2D CAD application for Windows, Apple and Linux. It is based on Qt, which is a leading cross-platform application and UI development framework.

AutoCAD is a software application for both 2D and 3D computer-aided design (CAD) and drafting — available since 1982 as a desktop application and since 2010 as a mobile web- and cloud-based app, currently marketed as Autocad 360.

DraftSight is a professional-grade, open 2D CAD product for users who want a better way to read, write and share DWG files. DraftSight is easy to use and is available for professional CAD users, students and educators to download and activate for free.*

SolveSpace is an Open Source 2D and 3D CAD (computer-aided design) program. It is a constraint-based parametric modeler with simple mechanical simulation capabilities. It is developed by Jonathan Westhues.

Autodesk® Inventor® products offer a comprehensive, flexible set of software for 3D mechanical design, product simulation, tooling creation, and design communication. Inventor takes you beyond 3D to Digital Prototyping by enabling you to design, visualize, and simulate your products.

A powerful CAD platform, with features familiar to you from native .dwg applications. BricsCAD® unifies advanced 2D design with the intelligence of 3D direct modeling. For Windows, Linux, and Mac.

NaroCAD is a fully fledged and extensible 3D parametric modeling CAD application.The goal of this project is to develop a fully fledged and extensible 3D CAD software based on the concept of parametric modeling of solids, comparable to well known solutions.These functionalities are interrelated through Model Associativity and are exposed through a GUI. The general usability specifications like saving, importing are described in General functionality specifications . The software can be extended through Plugins and programming interface. »

QCAD is an application for computer aided drafting in 2D. With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schemas and diagrams. QCad uses the AutoCAD DXF file format internally and to save and import files. AutoCAD DWG support is available as a commercial plugin.

DesignSpark Mechanical is a 3D modeling software reported to be easy to use so that all engineers will be able to create and share models.Designs can be linked directly to RS/Allied off-the-shelf components for automatic bill of materials generation, part numbers, and costs for included components.DesignSpark Mechanical can export to DXF, SketchUp, ECAD, OBJ, STEP, and STL formats. Since the software is free, designs can be shared in native electronic form for providing 3D models to your customers and sharing with other engineers and management involved with the project. Designs can be sent directly to rapid prototyping/3D printer devices for quick prototyping. »

SALOME can be used as standalone application for generation of CAD models, their preparation for numerical calculations and post-processing of the calculation results. SALOME can also be used as a platform for integration of the external third-party numerical codes to produce a new application for the full life-cycle management of CAD models.

TurboCAD is a CAD software suite, with several different feature levels. It is a competitor to the likes of Autodesk's AutoCAD program, and is used by engineers, architects and hobbyists.

Creo Elements/Pro – formerly Pro/ENGINEER – is the standard in 3D product design, featuring state-of-the-art productivity tools that promote best practices in design while ensuring compliance with your industry and company standards. Integrated, parametric, 3D CAD/CAM/CAE solutions allow you to design faster than ever, while maximizing innovation and quality to ultimately create exceptional products.

ArchiCAD offers computer aided solutions for handling all common aspects of aesthetics and engineering during the whole design process of the built environment — buildings, interiors, urban areas, etc.