There is likely a lot more railway traffic control software written in Simula ( "The basic simulation kernel, the TTS module based on the SIMON/TTS system, is today implemented in Simula and running on a UNIX platform." https://pdfs.semanticscholar.org/ed7e/d90fbc57b7ee0473d41edb... [2008] -- last listed author works for and the work is funded by Banverket, the Swedish National Rail Administration ) than in Ruby, and yet it's still rubyonrails.org.