_R5RS_

The "r5rs" collection implements the language defined by the
"Revised^5 Report on the Algorithmic Language Scheme" in the "lang.ss"
module.  In addition, this module provides _#%provide_ (instead of
`provide'), _#%require_ (instead of `#%require'), `#%app', `%datum',
etc.  The `letrec' of this language is defined exactly as in R5RS, and
not as in MzScheme.

You can use this collection in several ways:

* Use the "Standard (R5RS)" language in DrScheme.

* Write code in a module using the R5RS module (lib "lang.ss" "r5rs"),
  as a base language:

    (module foo (lib "lang.ss" "r5rs")
      ...)

  in this case, you can `provide' bindings and `require' other modules
  by using _#%require_ and _#%provide_.

* Start MzScheme using bindings from the R5RS language with

    mzscheme -M r5rs

  This will start MzScheme with only the R5RS bindings (with #%require
  etc), and a reader that will reject use of square brackets and curly
  braces.