[mtmail]

It's a semi-regular question, the HN archives have good pointers. E.g. https://news.ycombinator.com/item?id=21457029 https://news.ycombinator.com/item?id=17399340

Personally I'm impressed by https://docs.konghq.com/ and like the freshdesk.com layout, e.g. https://zapiet.freshdesk.com/en/support/solutions/articles/6... (more a knowledge base than base documentation)

[gus_massa]

@OP: Perhaps it is interesting if you add more information about why you want to know it.