good editor for R sources ?

(Sorry if the question has already been answered.)
Could someone please suggest a good text editor for
writing R sources ?
(I know emacs exists ... but I find it a bit heavy).
I use crimson (http://www.crimsoneditor.com) which is
small and simple, but the R syntax seems not to be supported.

See http://www.sciviews.org/_rgui/projects/Editors.html
The page tells us that there is support for Crimson editor.