FreeCalc.com has over fifteen engineering design applications developed by Beacon Engineers Inc, which are useful for quick calculations for work or research. The applications can be used freely online; to be able to save your work and get further benefits, a subscription is required. Categories include general engineering, liquid and gas flow, fans and HVAC, pumps, heat transfer, vessels and...

The Open System for Earthquake Engineering Simulation (OpenSees) is a project of the Pacific Earthquake Engineering Research Center. OpenSees is an open source "software framework for developing applications to simulate the performance of structural and geotechnical systems subjected to earthquakes." The project's homepage maintains resources for users and developers, including downloadable source...

A programmable logic controller (PLC) is an instrument used for many types of machine control. Instead of having to design complex circuitry, a PLC can be configured with software to do the job more efficiently. PLCS.net is a site with loads of useful tutorials and instructions that make the programming required to use these gadgets much easier. Many of the sections have animations that further...