> Unfortunately this zoo of extensions is very confusing to people who are
> not Scheme experts. There are now at least 11 of them, and all of them
> are cryptic acronyms.

Some can be considered obsolete in the R7RS world. Besides, having a
number of cryptic extensions seems the least problem to me.

Think of .c .cc .cpp .cxx .h .hh .hxx .hpp and another bunch of
extensions telling you whether to preprocess the source or not, etc.
This is the least problem with C++. :)