Ask HN: What has good backward compatibility?

[codingclaws]

[eternityforest]

Retro game console emulators USB 0.5 and 0.7mm pencils Spoken language dialects Web Browsers PDFs Power outlets FRS radios Metric screw threads

One of these days I want to make, unless someone else does it first, an awesome list that celebrates things that are thoroughly standardized.

[thesuperbigfrog]

Microsoft Windows:

https://www.neowin.net/news/fun-experiment-reveals-just-how-...

[akasakahakada]

Mathematics. Your new theory need to be compatible with proven theories.

[anonzzzies]

Windows, Common Lisp, PHP? What are you looking for specifically?