Designspark Mechanical!

SketchUp (formerly Google Sketchup) is a 3D modeling computer program for a wide range of drawing applications such as architectural, interior design, civil and mechanical engineering, film, and video game design—and available in a freeware version, SketchUp Make, and a paid version with additional functionality, SketchUp Pro.

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. »

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.

BRL-CAD is a powerful cross-platform open source solid modeling system that includes interactive geometry editing, high-performance ray-tracing for rendering and geometric analysis, image and signal-processing tools, a system performance analysis benchmark suite, libraries for robust geometric representation, with more than 20 years of active development.

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.

nanoCAD is a pro-grade 2D CAD system with native DWG support and full customizability. It is totally free, for business, professional, or personal purposes. It is fast, lightweight, capable, and , unlike most free CAD programs, completely uncrippled. nanoCAD includes:1. Classic CAD interface. Any engineer could easily master nanoCAD since everything is in their right places: menu, button icons, panels, command line, and the commands theirselves are easily recognizable. This makes nanoCAD easy to migrate to since enterprise needs no time to retrain its engineers.2. Native *.dwg support. The world’s most popular file format for technical documentation - *.dwg – is the nanoCAD native file format. Project created using nanoCAD and saved as *.dwg file could be easily opened and edited in any CAD application supporting *.dwg which in turn makes nanoCAD perfect tool for project collaboration and sharing.3. Ultimate design tool. nanoCAD includes all necessary tools required for basic design and allows creating and editing 2D and 3D vector primitives, texts, tables, blocks, graphical technical documentation display and print settings using either a model or a sheet. »

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. »

Browser based 3D solid CAD editor, Openscad style, with a Coffeescript based syntax, using only Coffeescript + Javascript

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.

CATIA (Computer Aided Three-dimensional Interactive Application) (in English usually pronounced /k?'ti?/) is a multi-platform CAD/CAM/CAE commercial software suite developed by the French company Dassault Systèmes. Written in the C++ programming language, CATIA is the cornerstone of the Dassault Systèmes product lifecycle management software suite.

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.