@amoroso Interesting read, thanks for the reference. I think I still have my copy of the Ironman spec somewhere. Having mostly just written Python for the last few years (retired, hobby programming) I had a good look round the ”modern” languages and decided I hated Go the least but did wonder if I should have a look at what's available now with Ada. This has rekindled that interest. Particularly, it was news to me that recent Ada has support for DbC. I've never actually written any Eiffel but did read Meyer's book on the subject with interest. Another language which doesn't get as much historical attention as it could is Simula67. AFAIK, it was the first language with classes and inheritance - not a small contribution.