R6RS macros with positional and optional arguments

[Makers ] is a distribution of libraries for R6RS Scheme implementations. In the paper:
Keyword and Optional Arguments in PLT Scheme“. Matthew Flatt and Eli Barzilay. 2009 Workshop on Scheme and Functional Programming.
the authors discuss ways to provide functions and macros with a mix of fixed and optional arguments to better organise abstractions. This package humbly proposes an alternative for R6RS implementations, without the use of “keywords” as disjoint type of values.

(via comp.lang.scheme)