Flight Gear Flight Simulator
The FlightGear flight simulator project is an open-source, multi-platform, cooperative flight simulator development project. Source code for the entire project is available. (OpenGL)[OS Independent]
http://www.flightgear.org/

FlightGear Flight Simulator
An open-source, multi-platform, cooperative flight simulator development project. Source code for the entire project is available and licensed under the GNU General Public License. The goal of the project is to create a sophisticated flight simulator framework for use in research or academic environments.
http://flightgear.sourceforge.net/

Flight Gear Flight Simulator
Open Source flight simulator. Source code is available here, and it can run on Windows, Linux, Mac platforms.
http://www.flightgear.org

Flight Science & Technology Research - University of Liverpool
The group is concerned with modelling and simulation of helicopter and airplane flight dynamic and control problems using FLIGHTLAB and a six degree of freedom flight simulator.
http://dbweb.liv.ac.uk/engdept/content/centres/fst/

Progress Flight Academy
Progress Flight Academy in South Africa
http://www.flightacademy.co.za/

Tradewinds Aviation
San Jose Flight School and Cessna Plane Sales. Leading San Francisco Bay Area Flight School and Pilot Training Facility
http://www.tradewindsaviation.com/

Squadron 2 Flying Club
Squadron2 is a user friendly flight club located at KRHV, in San Jose, California. Our rating and club requirements focus on being able to use the club efficiently without having to schedule repetative monthly instructor time to keep current.
http://www.squadron2.com/

Command Fliteware International Ltd
Manufacturers of high quality flight simulation and aerospace training equipment
http://www.commandfliteware.com/

Leo's Software
Downloadable flight Simulator for CE and HP48CE emulator.
http://www.leobueno.net/

Aviation Courses
Aviation Courses
http://www.aviationcourses.com/