This paper presents the outline of a module system for the Scheme
programming language in order to solve several problems commonly
encountered with contemporary implementations. These problems include
the lack of support for separate compilation and cross-module type
checking as well as the necessity for non-standard language extensions
to aid certain compiler optimizations like open compilation and
procedure in-lining.

Even though Scheme needs to be augmented with concepts like modules,
types, and signatures, this will not change the spirit of the language
in a major way. Instead it turns out that other recent additions to
the language interact smoothly with the proposed module system.

It will be emphasized that it is necessary to make a clean distinction
between syntactic definitions and value definition -- reflected by a
textual separation of modules and their signatures.