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      Kermit was perhaps the most widely ported non-trivial program in the world, appearing on hundreds of different operating system/machine combinations and they all could talk to each other reliably. It’s a truly amazing achievement.

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      The first real program that I wrote was a monitoring system that communicated with a telco TAP gateway (an actual mainframe in those days (mid 90s) via c-kermit. I have fond memories of the flexibility, and not so fond memories of the weird scripting language it used.