As I said, not another language, but another (more modern) dialect of the same language.
> In other words, the same ported and cleaned 3.1 sources that allegedly > was once used as a foundation for OS4
...and AmigaOS 3.5 and 3.9 before that.
> The Hyperion 3.1 binaries [...] based on rewritten/ported sources [...] > can have two outcomes: [...] 2) the small differences could [...] introduce > slightly different behavior and maybe even incompatibilities issues
AmigaOS 3.5 and 3.9 are quite backward compatible :-)
