IronCAD

Solid modeling software for mechanical designers and engineers.
http://www.ironcad.com/

SolidWorks

A solid modeling program for mechanical engineers and designers, as well as add-on applications.
http://www.solidworks.com/

SteelCad

Steel detailing software with packages for structural design, detailing, and manufacturing.
http://www.steelcad.com/

ProSpur+

A program designed to create drawings of spur gears, as symbols for ProCAD+ on Acorn RISC computers.
http://www.dsnell.zynet.co.uk/PS/ProSpur.html

freeCAD

A basic CAD program for creating collections of 3D elements, which can be connected by joints, constraints, actuators, springs, dampers, or forces for running motion simulations.
http://www.askoh.com/

Pilot3D

A relational trimmed NURB curve and surface 3D modeling program, useful for boat hulls and other applications.
http://www.pilot3d.com/

SnapCAD

A mechanical design software package for TEMA type shell and tube heat axchangers and ASME pressure vessels.
http://www.snapcad.com/

Autopipe

Software that calculates piping code stresses, loads, and deflections under static and dynamic loading conditions, with special features for buried pipeline analysis, wave loading, and fluid transients.
http://www.autopipe.com/

Autodesk Inventor

Solid modeling package for 3D mechanical design.
http://www.autodesk.com/inventor

MCS, Inc.

Makers of the Anvil Express software for mechanical design, that also has manufacturing features.
http://www.mcsaz.com/

CoCreate

Provider of engineering collaboration software for product design, management, and development, CAD, PLM, mechanical engineering, and workflow management.
http://www.cocreate.com/

VariCAD

2D/3D mechanical engineering CAD System for Windows and Linux.
http://www.varicad.com/

Ashlar Inc.

Vellum 3D CAD program and Vellum Solids 3D modeling software.
http://www.ashlar.com/

Function Bay, Inc.

Virtual prototyping of complex mechanical systems with the RecurDyn software products.
http://www.functionbay.com/

Engineering Software Solutions

Developers of engineering based design software for special requirements in industries such as petrochemical, ship building, mining, civil, mechanical, structual, manufacturing, defence and aerospace.
http://www.ess.com.au/

Think3

Produces mechanical CAD software for conceptual design through engineering to manufacturing for products in many industries.
http://www.think3.com/

Drew's MCAD Connection

A technical resource for users of Autodesk's MCAD products including Mechanical Desktop and Inventor.
http://www.mymcad.com/

Solid ConceptMecaSoft

Develops and sells SolidConcept, a parametric 3D solid modeling software for creating parts, assemblies and automatic 2D drawings.
http://www.solid-concept.com/

Sigmetrix LLC

Develops and supports CE/TOL, a tolerance and variation analysis software package for mechanical design and manufacturing processes.
http://www.sigmetrix.com/

Intergraph SmartSketch

A 2D parametric drawing program for Windows, that works on AutoCAD and MicroStation files.
http://www.intergraph.com/imagine/

CADables

TurboCAD hatch patterns, color palettes, and related resources.
http://catalog.stormloader.com/

Saga Software

TabletCAD is a computer program for designing medicinal tablet shapes, calculating tablet volume and surface area and producing tablet technical drawings.
http://simnet.is/sagasoftware/

Sheet Lightning

Specialized engineering 2D/3D CAD shareware for sheet metal design and unfolding for fabrication and manufacture. It handles cylinders, cones, square-to-round adapters, ovals, intersections and multi-intersections.
http://www.revcad.com/SheetLightning/default.htm

Zetaline Projects Limited

Presents the PipeData-Pro software family for piping designers and engineers [requires JavaScript and Flash].
http://www.pipedata.com/

Romax Technology

Develops software for gear box design, dynamic simulation of gear shift synchronization, and related tasks.
http://www.romaxtech.com/

Autodesk Inventor Tutorials by Sean Dotson

Basic and advanced tutorials on the use and customization of Autodesk Inventor 3D CAD software, discussion forums and current CAD news.
http://www.sdotson.com/

SketchCalc

A software that allows to calculate the properties of arbitrary profile sections, imported from DXF.
http://www.sketchcalc.com/

SeaSolution

CAD/CAM tool for geometric simulation and design focused at ship building and shell plates development.
http://www.seasolution.com/

Revware, inc.

Feature-based reverse engineering software for SolidWorks.
http://www.revworks.com/

Alibre Inc

Alibre Design is a low-cost parametric mechanical design application with CAD-neutral data sharing and online collaboration tools.
http://www.alibre.com/

Cadsoft Solutions, Inc.

Developer of Concepts Unlimited, 2D 3D modeling tools for Mac and PC designers. Supports precise NURBS,analytices, rendering, animiation and drawing composition.
http://www.concepts3d.com/

Washington Softwares Ltd.

Mechanical design software with 2-D drawing support for designing of centrifugal fans, pressure vessles (ASME & ISI standards), Gears, clutches, and couplings.
http://washingtonsoft.com/