I've guess I've used MIT and Chez which were native, and chicken and bigloo which are (from memory) going via c. So maybe biased my feeling that native wasn't

I've guess I've used MIT and Chez which were native, and chicken and bigloo which are (from memory) going via c. So maybe biased my feeling that native wasn't that unusual. But yes, imprecision in the original may have caused confusion. [update] I was curious, so had a look at https://get.scheme.org/ https://get.scheme.org/ Not sure how complete that list is, but that has 4 native compilers and 3 scheme-to-c, which I guess leaves the other dozen or so interpreted, but that gets muddied with intermediate languages and retargetable (e.g. gambit).