ion.pe
Powerful programmer's editor with integrated REBOL/Core interpreter. First editor with such integration. Description, documents, screenshots, time-limit download.
Kate syntax
Syntax highlighting for Kate, a programmer's editor for KDE/Linux.
REBOL mode for Emacs
Correct indentation and styling for REBOL coding in Emacs
reboLDAP
A project intended to develop REBOL tools for the Lightweight Directory Access Protocol.
VIM Syntax Files
Syntax highlighting in the VIM editor for REBOL source.