[kovrik]

I don't know, every time I check different common implementations (Racket, Guile, Chicken, Chez, Kawa) - they all act very different. Very often even a very simple code snippet works fine in one implementation, but not in the other(s).

And while writing my own Scheme, I literally had to choose "Ok, I will implement this Racket-way; This I will implement Guile-way" etc.

[Johnny_Brahms]

I have found that you fairly easily can write portable r6rs code, but whenever you step outside r6rs (for stuff that isn't standard, like networking) it becomes an exhibition of cond-expand abuse.