I've just uploaded an implementation of SRFI 19 to Snow Fort:

    http://snow-fort.org/pkg

This implementation is a lightly modified version of the standard implementation provided alongside the SRFI. The modifications were mainly to support running the library in Chibi Scheme.

    http://synthcode.com/wiki/chibi-scheme

To install it in Chibi Scheme, run the following command:

    snow-chibi install "(srfi 19)"

Many thanks for all your help!

    Geoff