I didn't find any previous mention of Geiser, a new Emacs interactivemode for Guile and PLT:
"Geiser is a generic Emacs/Scheme interaction mode, featuring anenhanced REPL and a set of minor modes improving Emacs' basic schememajor mode."
http://gitorious.org/geiser
Here was the note about its release:
http://programming-musings.org/2009/05/14/geiser/