McStas is an Open Source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 software simulator for neutron scattering

Neutron scattering

Neutron scattering,the scattering of free neutrons by matter,is a physical processand an experimental technique using this processfor the investigation of materials.Neutron scattering as a physical process is of primordial importance...

 experiments. The software consists of a compiler

Compiler

A compiler is a computer program that transforms source code written in a programming language into another computer language...

 that translates instrument and component definitions to C

C (programming language)

C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....

 code.

The basics of McStas was written in 1997 at Risø for simulation of their neutron experiments. It is currently developed at Risø (even though their reactors has been shut down) and Institut Laue-Langevin

Institut Laue-Langevin

The Institut Laue–Langevin, or ILL, is an internationally-financed scientific facility, situated in Grenoble, France. It is one of the world centres for research using neutrons...

, with recent added involvement from the Niels Bohr Institute

Niels Bohr Institute

The Niels Bohr Institute is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics....

 and Paul Scherrer Institute

Paul Scherrer Institute

The Paul Scherrer Institute is a multi-disciplinary research institute which belongs to the Swiss ETH-Komplex covering also the ETH Zurich and EPFL...

. Involvement from European Spallation Source

European Spallation Source

European Spallation Source is the name of a materials research facility for scientific research using the neutron scattering technique. The facility will be built in Lund, Sweden starting in 2013. The facility is expected to open in 2019 and will be fully operational in 2025...

 is expected soon, since the Swedish

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

/Danish

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 bid won.

Official partner sites are

• Risø DTU
• Institut Laue-Langevin
  Institut Laue-Langevin
  The Institut Laue–Langevin, or ILL, is an internationally-financed scientific facility, situated in Grenoble, France. It is one of the world centres for research using neutrons...
  
  
• Niels Bohr Institute
  Niels Bohr Institute
  The Niels Bohr Institute is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics....
  
  
• Paul Scherrer Institute
  Paul Scherrer Institute
  The Paul Scherrer Institute is a multi-disciplinary research institute which belongs to the Swiss ETH-Komplex covering also the ETH Zurich and EPFL...