Viewing preview of files in finder I have some .groovy files on my file system.  I would like to be able to preview them in Finder as I navigate around them.  How do I do this?
QLStephen displays files with no extension or with arbitrary extensions as plain text. You can install it by moving the qlgenerator bundle to ~/Library/QuickLook/ and running qlmanage -r.

If it doesn't display some file types, try adding their UTIs to CFBundleDocumentTypes:LSContentTypes in the Info.plist.