Environmental Simulation Center
The Environmental Simulation Center is an independent, not-for-profit planning and urban design firm, specializing in applying information technology and decision support systems in real-world planning, design, development, and environmental and visual impact projects.
http://www.simcenter.org/

Simulation and environmental modeling links
Interesting links in: Modeling and Simulation, Environmental Decision Support Systems.
http://www.idsia.ch/~andrea

ACIMS -- Arizona Center of Integrated Modeling & Simulation
Artificial Intelligence and Simulation Group. The page contains summaries of ACIMS simulation projects, simulation links, and news. One of the main research projects is the Discrete Event Specification Formalism (DEVS).
http://www.acims.arizona.edu/

Averill M. Law and Associates
Averill M. Law & Associates offers simulation consulting, simulation training, and the ExpertFit distribution-fitting software. It was founded in 1977.
http://www.averill-law.com/

Tau Simulation
Tau Simulation produces high performance simulation software for integrated circuit verification
http://www.tausim.com/

CADwalk
Process simulation, device simulation, and circuit simulation as services. Specialties include working with SiGe HEMT, HBT, and MOSFET.
http://www.cadwalk.de/

C++SIM
_your description goes here_
http://cxxsim.ncl.ac.uk/

Vicinities.com -
The Simulation Zone Users Forum has been created for individuals to effectively share simulation knowledge and information online. It contains links to important simulation sites.
http://www.communityzero.com/simzone/

Simulation Tools
A Collection of Modelling and Simulation Resources on the Internet for the simulation of both continuous-time dynamic systems and discrete-event ones. Provides a broad review with links to the software.
http://www.idsia.ch/~andrea/simtools.html

Industrial studies based on simulation
Simulation de flux pour l'aide à la décision de systèmes industriels et scientifiques
http://www.1point2.com