http://www.essex.ac.uk/dces/people/profile.aspx?id=124
http://www.eecs.umich.edu/gasm/
http://rotor.di.unipi.it/AsmCenter/default.aspx
http://www.ldl.jaist.ac.jp/cafeobj
http://www.cofi.info
http://eventb.loria.fr
http://www.iist.unu.edu/raise
http://research.microsoft.com/users/lamport/tla/tla.html
http://www.vdmportal.org
