Bridges by GarageGames

Released previously as Chronic Logic's Pontifex II, Bridge Construction Set challenges players to build bridges of varying complexity over a river and then see if their design can support a train.

The software employs a complex physics model and enables users to view their creation from any angle. A level editor is also included.

A demo with a tutorial and five levels for both Windows and Linux is available at the companysite or from the link below. The full version is available for $19.95.