Scheme as defined in R5RS is not case sensitive when reading symbols. Guile, on the contrary is case sensitive by default, so the identifiers
guile-whuzzy Guile-Whuzzy
are the same in R5RS Scheme, but are different in Guile.
It is possible to turn off case sensitivity in Guile by setting the
reader option case-insensitive. For more information on reader
options, See Reading Scheme Code.
(read-enable 'case-insensitive)
It is also possible to disable (or enable) case sensitivity within a
single file by placing the reader directives #!fold-case (or
#!no-fold-case) within the file itself.