(This article was first published on Dataninja » R, and kindly contributed to R-bloggers)
Via this page, I just learned that there is a TextWrangler Language Module for R. The file itself is available here.
To install, copy the .plist file to the following directory
Username/Library/Application Support/TextWrangler/Language Modules
I also recommend going into TextWrangler’s preferences and changing the color for comments. The default is a gray color that doesn’t provide a lot of contrast compared to normal black screen text.
Also, check out the via page from SciViews.com. It has links to R syntax highlighting files for many editors on many platforms.
To leave a comment for the author, please follow the link and comment on his blog: Dataninja » R.
R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series,ecdf, trading) and more...

Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).