chez : A programming language based on R6RS ( https://cisco.github.io/ChezScheme/ https://github.com/cisco/ChezScheme )
chibi : Minimal Scheme implementation for use as an extension language ( http://synthcode.com/scheme/chibi/ )
cyclone : R7RS Scheme to C compiler ( http://justinethier.github.io/cyclone/ )
gerbil : Dialect of Scheme designed for Systems Programming ( https://cons.io/ https://github.com/vyzo/gerbil )
guile-colorized : Colorized REPL for GNU Guile ( https://gitlab.com/NalaGinrut/guile-colorized/ )
guile-gi : Bindings for GObject Introspection and libgirepository for Guile ( https://spk121.github.io/guile-gi/ )
owl-lisp : Purely functional dialect of Scheme ( https://haltp.org/posts/owl.html )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a guru
For Paludis use this rsync : rsync://gentoo.zugaina.org/guru-portage
If you have a problem : ycarus(-at-)zugaina.org