spin - 6.4.9+dfsg-1 main

Spin is a popular open-source software verification tool, used by thousands
of people worldwide. The tool can be used for the formal verification of
multi-threaded software applications. The tool was developed at Bell Labs
in the Unix group of the Computing Sciences Research Center, starting in 1980.
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The software has been available freely since 1991, and continues to evolve to
keep pace with new developments.
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In April 2002 the tool was awarded the ACM System Software Award.