In scope is anything of note in technology/programming that is Danish, Estonian, Finnish, Icelandic, Norwegian or Swedish. I've included the main authors based on Wikipedia articles.
A lot of these were created by people while abroad (mainly in the US) but I still list them here as it's interesting to see how much people from such a small part of the world have contributed. Similarly, things built in the Nordic countries by a multitude of nationalities may be included (e.g. Erlang).
- 1960 - ALGOL 60 "Report on the Algorithmic Language ALGOL 60". Peter Naur (Denmark)
- 1965 - SIMULA. Ole-Johan Dahl & Kristen Nygaard (Norway) https://en.wikipedia.org/wiki/Simula
- 1967 - First Object Oriented Programming language (SIMULA 67). Ole-Johan Dahl & Kristen Nygaard (Norway) https://en.wikipedia.org/wiki/Object-oriented_programming#History
- 1983 - Turbo Pascal. Anders Hejlsberg (Denmark) https://en.wikipedia.org/wiki/Turbo_Pascal
- 1985 - C++. Bjarne Stroustrup (Denma